Liquid crystal panel and method of manufacturing thereof

ABSTRACT

A liquid crystal panel includes a first substrate including multiple pixel electrodes; a liquid crystal layer; and a second substrate including a common electrode. In at least 30 pixels consecutive in a row direction, arrays of the domains are identical, the domains in the display unit region located in an nth row are arranged in an order of a first domain, a second domain, a third domain, and a fourth domain, and each of the pixel electrodes includes a first pixel electrode having a configuration in which fine slits parallel to an alignment vector of the corresponding domain are provided in at least one of a region superimposed on the first domain, a region superimposed on the second domain, a region superimposed on the third domain, or a region superimposed on the fourth domain while the fine slits are not provided in the remaining regions.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 toJapanese Patent Application No. 2018-062301 filed on Mar. 28, 2018, thecontents of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a liquid crystal panel and a method ofmanufacturing thereof. More particularly, the present invention relatesto a liquid crystal panel having a configuration in which one pixel isdivided into multiple alignment regions (domains) and a method suitablefor manufacturing of the liquid crystal panel.

Description of Related Art

A liquid crystal display device is a display device in which a liquidcrystal composition is used to perform display. In a typical displaysystem for the liquid crystal display device, the liquid crystalcomposition enclosed between a pair of substrates is irradiated with,light from a backlight, and voltage is applied to the liquid crystalcomposition to change alignment of liquid crystal molecules, therebycontrolling an amount of light transmitted through the liquid crystalpanel. Because the liquid crystal display device has the features suchas a low profile, light weight, and low power consumption, the liquidcrystal display device is used in electronic products such as asmartphone, a tablet PC, and an automotive navigation system.

Conventionally, an alignment division technique have been studied. Inthe alignment division technique, one pixel is divided into multiplealignment regions (domains), and the liquid crystal molecules arealigned at different azimuths in different alignment regions, therebyimproving a viewing angle characteristic. JP 2015-31961 A can be citedas an example of a citation list disclosing the alignment divisiontechnique.

A liquid crystal display device disclosed in JP 2015-31961 A includes: adisplay substrate that includes multiple pixel regions and has a curvedshape bent according to a first direction; a counter substrate that isopposed and coupled to the display substrate and has a curved shapetogether with the display substrate; and a liquid crystal layer disposedbetween the display substrate and the counter substrate. In the liquidcrystal display device, multiple domains are defined in each of thepixel regions, at least two of the domains are different from each otherin a direction in which liquid crystal molecules of the liquid crystallayer are aligned, and the domains are arrayed in a second directioncrossing the first direction.

BRIEF SUMMARY OF THE INVENTION

In the liquid crystal panel in which the alignment division technique isused, a fine slit is occasionally formed in a pixel electrode. However,a line width of the fine slit with high accuracy is hardly controlled,and luminance unevenness (transmittance unevenness) is occasionallygenerated due to a variation in line width.

The present invention has been made in view of such a current state ofthe art and aims to provide a liquid crystal panel in which theluminance unevenness due to the variation in line width of the fine slitis suppressed and a method suitable for manufacturing of the liquidcrystal panel.

The inventors have found that luminance unevenness is generated due tothe variation in line width of the fine slit formed in the pixelelectrode. Coexistence of a region where the fine slit is provided inthe pixel electrode and a region where the fine slit is not provided inthe pixel electrode reduces the luminance unevenness. Thereby, theinventors have arrived at the solution to the above problem, completingthe present invention.

That is, according to one aspect of the present invention, there isprovided a liquid crystal panel including, in the following order: afirst substrate including multiple pixel electrodes arranged into amatrix form and a first alignment film; a liquid crystal layercontaining liquid crystal molecules; and a second substrate including acommon electrode and a second alignment film, wherein an alignmentvector is defined as being from a first substrate side long-axis end ofeach of the liquid crystal molecules, a start point, to a secondsubstrate side long-axis end of the liquid crystal molecule, an endpoint, and the first alignment film and the second alignment film havingbeen subjected to an alignment treatment each include a first domain inwhich a direction of the alignment vector is a first direction, a seconddomain in which a direction of the alignment vector is a seconddirection, a third domain in which a direction of the alignment vectoris a third direction, and a fourth domain in which a direction of thealignment vector is a fourth direction, in a column direction in eachdisplay unit region superimposed on one of the pixel electrodes, in atleast 30 pixels consecutive in a row direction, arrays of the domainsare identical, the domains in the display unit region located in an nthrow, where n is any integer of 1 or more, are arranged in an order ofthe first domain, the second domain, the third domain, and the fourthdomain, and each of the pixel electrodes includes a first pixelelectrode having a configuration in which fine slits parallel to thealignment vector of the corresponding domain is provided in at least oneof a region superimposed on the first domain, a region superimposed onthe second domain, a region superimposed on the third domain, or aregion superimposed on the fourth domain while the fine slits are notprovided in the remaining regions.

According to another aspect of the present invention, there is provideda method of manufacturing the liquid crystal panel of the above aspect,the method including forming the fine slits by photolithography, thephotolithography including irradiating a photosensitive resin formed ona conductive film with light through a mask in which a patterncorresponding to the fine slits is formed and multiple lenses.

The present invention can provide the liquid crystal panel in which theluminance unevenness due to the variation in line width of the fine slitis suppressed and the method suitable for manufacturing of the liquidcrystal panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view schematically illustrating an exampleof a liquid crystal display device of an embodiment;

FIG. 2 is a plan view schematically illustrating an arrangement relationof an oblique azimuth of liquid crystal molecules in a liquid crystallayer of the embodiment and a color filter of a second substrate;

FIG. 3 is a view illustrating a relationship between the oblique azimuthof the liquid crystal molecules and an alignment vector;

FIG. 4 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate of the embodiment;

FIG. 5 is a view illustrating photolithography using a multi-lens;

FIG. 6A is a schematic cross-sectional view illustrating an arrangementrelation of the lenses in the multi-lens, and FIG. 6B is a conceptualview illustrating a pattern of luminance unevenness generated when apixel electrode including fine slits is formed by scanning exposure inwhich the multi-lens in FIG. 6A is used;

FIG. 7 is a graph illustrating a relationship between gray scale ofliquid crystal display in the liquid crystal panel of the embodiment andtransmittance with respect to each of a fine slit region, a solidregion, and a total of the fine slit region and the solid region;

FIG. 8 is a graph illustrating a ratio (fine slit contribution ratio) oftransmittance of the fine slit region to the total of transmittances ofthe fine slit region and the solid region for each gray scale value ofthe liquid crystal display;

FIG. 9 is a schematic diagram illustrating an example of a photoalignment treatment device;

FIG. 10 is a view illustrating an example of a photo alignment treatmentstep using the photo alignment treatment device;

FIG. 11A is a view illustrating the photo alignment treatment performedon a TFT substrate (first substrate), FIG. 11B is a view illustratingthe photo alignment treatment performed on a CF substrate (secondsubstrate), and FIG. 11C is a view illustrating a state after bonding ofthe TFT substrate and the CF substrate that are subject to the photoalignment treatment;

FIG. 12 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate according to a first modification;

FIG. 13 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate according to a second modification;

FIG. 14 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate according to a third modification;

FIG. 15 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate according to a fourth modification;

FIG. 16 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate according to a fifth modification;

FIG. 17 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules in the liquid crystal layer while the obliqueazimuth is superposed on an example of an electrode and line structureof a first substrate according to a sixth modification;

FIGS. 18A to 18E are schematic plan views each illustrating an exampleof an arrangement pattern of the fine slits;

FIGS. 19A and 19B are schematic plan views each illustrating an exampleof the arrangement pattern of the fine slits;

FIGS. 20A and 20B are views each illustrating the case that the liquidcrystal panel of the embodiment is bent, FIG. 20A illustrates the statein which the liquid crystal panel is not bent, and FIG. 20B illustratesthe state in which the liquid crystal panel is bent;

FIGS. 21A and 21B are views each illustrating a state of a dark line ina portion where misalignment is not generated in the liquid crystalpanel of the embodiment, FIG. 21A is a plan view of a pixel, and FIG.21B is a cross-sectional view taken along line A-A′;

FIGS. 22A and 22B are views each illustrating the state of the dark linein a portion in which the misalignment of a first form is generated inthe liquid crystal panel of the embodiment, FIG. 22A is a plan view ofthe pixel, and FIG. 22B is a cross-sectional view taken along line A-A′;

FIGS. 23A and 23B are views each illustrating the state of the dark linein a portion in which the misalignment of a second form is generated inthe liquid crystal panel of the embodiment, FIG. 23A is a plan view ofthe pixel, and FIG. 23B is a cross-sectional view taken along line A-A′;

FIGS. 24A and 24B are views each illustrating the case that a firstconventional liquid crystal panel is bent, FIG. 24A illustrates thestate in which the first conventional liquid crystal panel is not bent,and FIG. 24B illustrates the state in which the first conventionalliquid crystal panel is bent;

FIGS. 25A and 25B are views each illustrating the state of the dark linein a portion in which the misalignment is not generated in the firstconventional liquid crystal panel, FIG. 25A is a plan view of the pixel,and FIG. 25B is a cross-sectional view taken along line A-A′;

FIGS. 26A and 26B are views each illustrating the state of the dark linein a portion in which the misalignment of the first form is generated inthe first conventional liquid crystal panel, FIG. 26A is a plan view ofthe pixel, and FIG. 26B is a cross-sectional view taken along line A-A′;

FIGS. 27A and 27B are views each illustrating the state of the dark linein a portion in which the misalignment of the second form is generatedin the first conventional liquid crystal panel, FIG. 27A is a plan viewof the pixel, and FIG. 27B is a cross-sectional view taken along lineA-A′;

FIGS. 28A and 28B are views each illustrating the case that a secondconventional liquid crystal panel is bent, FIG. 28A illustrates thestate in which the second conventional liquid crystal panel is not bent,and FIG. 28B illustrates the state in which the second conventionalliquid crystal panel is bent;

FIGS. 29A and 29B are views each illustrating the state of the dark linein a portion in which the misalignment is not generated in the secondconventional liquid crystal panel, FIG. 29A is a plan view of the pixel,and FIG. 29B is a cross-sectional view taken along line A-A′;

FIGS. 30A and 30B are views each illustrating the state of the dark linein a portion in which the misalignment of the first form is generated inthe second conventional liquid crystal panel, FIG. 30A is a plan view ofthe pixel, and FIG. 30B is a cross-sectional view taken along line A-A′;

FIGS. 31A and 31B are views each illustrating the state of the dark linein a portion in which the misalignment of the second form is generatedin the second conventional liquid crystal panel, FIG. 31A is a plan viewof the pixel, and FIG. 31B is a cross-sectional view taken along lineA-A′;

FIGS. 32A and 32B are views each illustrating the case that a thirdconventional liquid crystal panel is bent, FIG. 32A illustrates thestate in which the third conventional liquid crystal panel is not bent,and FIG. 32B illustrates the state in which the third conventionalliquid crystal panel is bent;

FIGS. 33A and 33B are views each illustrating the state of the dark linein a portion in which the misalignment is not generated in the thirdconventional liquid crystal panel, FIG. 33A is a plan view of the pixel,and FIG. 33B is a cross-sectional view taken along line A-A′;

FIGS. 34A and 34B are views each illustrating the state of the dark linein a portion in which the misalignment of the first form is generated inthe third conventional liquid crystal panel, FIG. 34A is a plan view ofthe pixel, and FIG. 34B is a cross-sectional view taken along line A-A′;and

FIGS. 35A and 35B are views each illustrating the state of the dark linein a portion in which the misalignment of the second form is generatedin the third conventional liquid crystal panel, FIG. 35A is a plan viewof the pixel, and FIG. 35B is a cross-sectional view taken along lineA-A′.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of the present invention will be described.However, the following embodiment is not intended to limit the scope ofthe present invention, and appropriate modifications can be made withinthe spirit of the present invention.

Embodiment

FIG. 1 is a cross-sectional view schematically illustrating an exampleof a liquid crystal display device of an embodiment. As illustrated inFIG. 1, the liquid crystal display device of the embodiment includes aliquid crystal panel 100 and a backlight 110 disposed on a back side ofthe liquid crystal panel 100. The liquid crystal panel 100 includes aback-side polarizing plate 20, a first substrate 30 including multiplepixel electrodes 35 and a first alignment film 71, a liquid crystallayer 40 containing liquid crystal molecules 41, a second substrate 50including a second alignment film 72 and a counter electrode (commonelectrode) 51, and a display-surface-side polarizing plate 60 in thisorder. The liquid crystal panel 100 includes a sealing material 80around the liquid crystal layer 40.

A method of displaying the liquid crystal display device of theembodiment will be described. In the liquid crystal display device ofthe embodiment, light is incident on the liquid crystal panel 100 fromthe backlight 110, and an amount of light transmitted through the liquidcrystal panel 100 is controlled by switching the alignment of the liquidcrystal molecules 41 in the liquid crystal layer 40. The alignment ofthe liquid crystal molecules 41 is switched by applying voltage to theliquid crystal layer 40 using the multiple pixel electrodes 35 and thecounter electrode 51. When the voltage applied to the liquid crystallayer 40 is less than a threshold (at time of applying no voltage), theinitial alignment of the liquid crystal molecules 41 is controlled bythe first alignment film 71 and the second alignment film 72.

At the time of applying no voltage, the liquid crystal molecules 41 arealigned substantially vertically to the first substrate 30 and thesecond substrate 50. As used herein, the term “substantially vertically”means that the liquid crystal molecules 41 are aligned slightly obliqueto the first substrate 30 and the second substrate 50 by the alignmenttreatment performed on the first alignment film 71 and the secondalignment film 72. A pre-tilt angle of the liquid crystal molecules 41with respect to the first substrate 30 and the second substrate 50 atthe time of applying no voltage is preferably greater than or equal to85° and less than 90°. When the voltage is applied between the pixelelectrode 35 and the counter electrode 51, a vertical electric field isgenerated in the liquid crystal layer 40, and the liquid crystalmolecules 41 are further obliquely aligned while an oblique azimuth ismaintained from the time of applying no voltage.

The oblique azimuth of the liquid crystal molecules 41 will be describedas appropriate using an alignment vector in which in a plan view of theliquid crystal panel 100, a first substrate 30 side long-axis end ofeach liquid crystal molecule 41 is defined as a start point(hereinafter, also referred to as “a tail of a liquid crystal director”)41S while the second substrate 50 side long-axis end of the liquidcrystal molecule 41 is defined as an end point (hereinafter alsoreferred to as “a head of the liquid crystal director”) 41T. Thealignment vector is in the same direction as the oblique azimuth of theliquid crystal molecules 41 with respect to the first alignment film 71on the side of the first substrate 30 and is in an opposite direction tothe oblique azimuth of the liquid crystal molecules 41 with respect tothe second alignment film 72 on the side of the second substrate 50. Asused herein, the term “azimuth” means a direction in a view projectedonto a substrate surface without consideration of an inclination angle(a polar angle, the pre-tilt angle) from a normal direction of thesubstrate surface. The liquid crystal molecules 41 are alignedsubstantially vertically (aligned slightly obliquely) at the time ofapplying no voltage, and are largely obliquely aligned at the time ofapplying the voltage while the oblique azimuth at the time of applyingno voltage is maintained, so that the start point 41S and the end point41T of the alignment vector may be checked while the voltage is appliedto the liquid crystal layer 40.

Preferably the first alignment film 71 and the second alignment film 72are each a photo alignment film in which a photo alignment film materialis deposited to exert a function of aligning the liquid crystalmolecules 41 in a specific direction by performing a photo alignmenttreatment. The photo alignment film material means a general materialthat generates a structural change when irradiated with light(electromagnetic wave) such as ultraviolet light and visible light,thereby exerting an ability of controlling the alignment of the nearbyliquid crystal molecules 41 (alignment controlling force) or changingthe alignment controlling force level and/or direction. For example, thephoto alignment film material includes a photoreactive site in which areaction such as dimerization (dimer formation), isomerization, photoFries rearrangement, and decomposition is generated by lightirradiation. Examples of the photoreactive sites (functional groups)that dimerize and isomerize by the light irradiation include cinnamate,cinnamoyl, 4-chalcone, coumarin, and stilbene. Azobenzene can be citedas an example of the photoreactive site (functional group) thatisomerizes by the light irradiation. A phenol ester structure can becited as an example of the photoreactive site that undergoes the photoFries rearrangement by the light irradiation. Dianhydride containing acyclobutane ring such as 1,2,3,4-cyclobutanetetracarboxylic acid-1, 2:3, 4-dianhydride (CBDA) can be cited as an example of the photoreactivesite that is decomposed by the light irradiation. Preferably the photoalignment film material exhibits vertical alignability that can be usedin a vertical alignment mode. Examples of the photo alignment filmmaterials include polyamide (polyamic acid), polyimide, polysiloxanederivative, methyl methacrylate, and polyvinyl alcohol that contain thephotoreactive site.

FIG. 2 is a schematic plan view illustrating an arrangement relation ofthe oblique azimuth of the liquid crystal molecules 41 in the liquidcrystal layer 40 of the embodiment and a color filter of the secondsubstrate 50. As illustrated in FIG. 2, in the liquid crystal panel 100of the embodiment, multiple pixels 10 are arranged into a matrix form ofN rows and M columns (N and M are integers of 1 or more). As usedherein, the pixel 10 means a display unit region superimposed on asingle pixel electrode 35, and a pixel superimposed on a color filter ofR (red), a pixel superimposed on a color filter of G (green), and apixel superimposed on the color filter of B (blue) are provided in thepixel 10. In FIG. 2, a portion surrounded by a one dot chain line is onepixel. Stripe-shaped color filters extending in the column direction arearranged on the second substrate 50 in order of R, G, B in the rowdirection. That is, the arrangement order of the pixels 10 in the rowdirection is repetition of the R pixel, the G pixel, and the B pixel,and the pixels 10 having the identical color are consecutively arrangedin the column direction.

Four domains having different alignment vectors are provided in eachpixel 10. These domains can be formed by varying the alignment treatmentperformed on the first alignment film 71 and the second alignment film72. When the voltage is applied to the liquid crystal layer 40, theliquid crystal molecules 41 are obliquely aligned so as to be matchedwith each of the alignment vectors of multiple domains.

In FIG. 2, in order to easily understand the oblique azimuth of theliquid crystal molecules 41, the liquid crystal molecules 41 arerepresented by pins (cones), the bottom surface of the cone representsthe side of the second substrate 50 (observer side), and a vertex of thecone represents the side of the first substrate 30. FIG. 3 is a viewillustrating a relationship between the oblique azimuth of the liquidcrystal molecules and the alignment vector.

The domains in the pixel located in the nth row (n is any integergreater than or equal to 1) are arranged in the order of a first domain10 a in which the direction of the alignment vector is a firstdirection, a second domain 10 b in which the direction of the alignmentvector is a second direction, a third domain 10 c in which the directionof the alignment vector is a third direction, and a fourth domain 10 din which the direction of the alignment vector is a fourth direction.The group of identical-color pixels consecutive in the column directionmay include the pixels 10 in which the arrangement order of the fourdomains varies. Specifically, the domains in the pixel (the (n+1)th rowpixel) located in the (n+1)th row adjacent to the nth row preferablysatisfy the relationship in which the first domain 10 a and the fourthdomain 10 d are located between the second domain 10 b and the thirddomain 10 c. As illustrated in FIG. 2, more preferably the domains inthe (n+1)th row pixel are arranged in the order of the third domain 10c, the fourth domain 10 d, the first domain 10 a, and the second domain10 b. Two kinds of pixels having different arrangement order of the fourdomains may be alternately and repeatedly arranged in the group ofidentical-color pixels consecutive in the column direction. In otherwords, pixels having different domain arrangement order may be arrangedin two row periods. In this case, as illustrated in FIG. 2, the domainsin the pixel located in the (n+2)th row are arranged in the order of thefirst domain 10 a, the second domain 10 b, the third domain 10 c, andthe fourth domain 10 d.

From the viewpoint of obtaining a good viewing angle characteristic, thealignment vectors of the first domain 10 a, the second domain 10 b, thethird domain 10 c, and the fourth domain 10 d are a combination of fouralignment vectors that face in directions different from one another by90°. The alignment vector of each domain can be decided by the directionof the liquid crystal molecules 41 located in the center of the domainin a plan view and located in the center of the liquid crystal layer ina cross-sectional view.

In the domain arrangement of FIG. 2, in the nth row pixel, the firstdomain 10 a and the fourth domain 10 d are located on the end side ofthe pixel, and the second domain 10 b and the third domain 10 c arelocated on the center side of the pixel. In the (n+1)th row pixel, thesecond domain 10 b and the third domain 10 c are located on the end sideof the pixel, and the first domain 10 a and the fourth domain 10 d arelocated on the center side of the pixel. Thus, in the domain arrangementillustrated in FIG. 2, each of the domain group located on the centerside of the pixel and the domain group located on the end side of thepixel is constructed with a combination of the first domain 10 a, thesecond domain 10 b, the third domain 10 c, and the fourth domain 10 dthat face in directions different from one another by 90°.

From the viewpoint of suppressing a dark line generated between thedomains, in a plan view of the nth row pixel, the alignment vectors ofthe first domain 10 a, the second domain 10 b, the third domain 10 c,and the fourth domain 10 d preferably have the following relationships(1) to (3).

(1) The alignment vectors of the first domain 10 a and the second domain10 b have a relationship, in which the end points are opposed to eachother and the alignment vectors are orthogonal to each other (forming anangle of about 90°)(hereinafter referred to as “a domain boundarycondition A”).

(2) The alignment vectors of the second domain 10 b and the third domain10 c have a relationship, in which the start points are opposed to eachother and the alignment vectors are parallel to each other (forming anangle of about 180°)(hereinafter referred to as “a domain boundarycondition B”).

(3) The alignment vectors of the third domain 10 c and the fourth domain10 d have the relationship (domain boundary condition A), in which theend points are opposed to each other and the alignment vectors areorthogonal to each other (forming the angle of about 90°).

As used herein, in the term “orthogonal (forming the angle of about90°)”, the alignment vectors may be substantially orthogonal to eachother within a range where the effect of the present invention isobtained, specifically the term “orthogonal” means that the alignmentvectors form an angle of 75° to 105°, preferably an angle of 80° to100°, more preferably an angle of 85° to 95°. In the term “parallel(forming an angle of about 180°)”, the alignment vectors may besubstantially parallel to each other within the range where the effectof the present invention is obtained, specifically the term “parallel”means that the alignment vectors form an angle of −15° to +15°,preferably an angle of −10° to +10°, more preferably an angle of −5° to+5°.

The dark line is formed due to discontinuity of the alignment of theliquid crystal molecules 41 at a boundary between the domains havingdifferent alignment azimuths of the liquid crystal molecules 41. In theregion where the alignment of the liquid crystal molecules 41 isdiscontinuous, because the liquid crystal molecules 41 cannot be alignedin an intended direction, the light can insufficiently be transmittedduring display, and the region is recognized as a dark portion. The darkportion formed in a linear shape is called the dark line. When the darkline is generated, transmittance (contrast ratio) of the pixel 10decreases, so that light use efficiency of the liquid crystal panel 100is degraded. In recent years, high definition of the pixel 10 hasadvanced and an area per pixel is reduced, but an area of the dark linedoes not change even if the pixel 10 is reduced, so that an area ratiooccupied by the dark line in the pixel 10 increases, and thereforeprevention of the degradation of the light use efficiency becomes moreimportant. When the dark line is generated at a different position ineach pixel 10, uniformity of the display is also degraded. On the otherhand, the inventors have studied that a generation situation of the darkline changes according to the arrangement of the domains, and have foundthat the arrangement of the domain boundary conditions A-B-A satisfyingall of the relationships (1) to (3) effectively suppresses the darkline.

In the first domain 10 a, the second domain 10 b, the third domain 10 c,and the fourth domain 10 d, an inter-substrate twist angle of the liquidcrystal molecules 41 is preferably less than or equal to 45°, morepreferably about 0°. That is, in the first domain 10 a, the seconddomain 10 b, the third domain 10 c, and the fourth domain 10 d, an angleformed between the oblique azimuth of the liquid crystal molecules 41with respect to the first alignment film 71 on the side of the firstsubstrate 30 and the oblique azimuth of the liquid crystal molecules 41with respect to the second alignment film 72 on the side of the secondsubstrate 50 is preferably less than or equal to 45°, more preferablyabout 0°.

In the liquid crystal panel 100 of the embodiment, as illustrated inFIG. 2, the arrangement order (domain array) of the first domain 10 a,the second domain 10 b, the third domain 10 c, and the fourth domain 10d is identical in at least 30 pixels consecutive in the row direction.The identical-domain-array pixels arranged consecutively in the rowdirection preferably have at least a ratio of one half to the totalnumber of pixels in the row direction of the display region, morepreferably at least a ratio of 90% to the total number of pixels in therow direction of the display region. Further preferably the pixelsarranged in the row direction in the entire display region have the samedomain array. The pixels arranged in the row direction can have the samedomain array by performing the alignment treatment on the firstalignment film 71 and the second alignment film 72 using scanningexposure. For example, the scanning exposure may be performed using aphoto alignment treatment device in FIG. 9.

The domain arrays of pixels arranged consecutively in the row directionare made identical, which allows the suppression of the generation ofdefects due to misalignment in a lateral direction (row direction) ofthe liquid crystal panel 100. Specifically, the generation of a displaydefect such as display unevenness due to bending of the liquid crystalpanel 100 can be suppressed, and the effect that suppresses thegeneration of the display defect appears notably in ahigher-added-value, large-sized, and high-definition liquid crystalpanel. Consequently, the liquid crystal panel 100 of the embodiment cansuitably be used for a higher-added-value, large-sized, andhigh-definition liquid crystal display in which excellent displayquality is required. The liquid crystal panel 100 of the embodiment canalso be used for a high-designability, large-sized, high-definitioncurved (non-planar) display. A method of thickening a light shieldingbody is adopted as another method of improving the display unevenness,but the transmittance decreases in this method. In particular, becausethe high-definition liquid crystal panel has the low transmittance, thefurther decrease in transmittance causes a serious problem such as aloss of marketability.

The liquid crystal panel 100 tends to become larger, lighter (thinningof the glass substrate), and higher definition. The liquid crystal panel100 that becomes larger and lighter is easily bent, and particularlyeasily bent in a long-side direction (row direction). When the liquidcrystal panel 100 is bent, the fitting between the first substrate 30and the second substrate 50 is partially and irregularly misaligned. Fora conventional liquid crystal panel having a multi-domain structure,when the misalignment is generated, a width and a shape of the dark lineat the domain boundary change, and the transmittance changes, so thatthe display unevenness is generated. The display unevenness is abelt-shaped unevenness extending from an upper end to a lower end of theliquid crystal panel, and is sometimes generated at an irregularposition, which sometimes significantly degrades the display quality ofthe entire liquid crystal panel. The display unevenness tends to beeasily generated in a relatively-expensive, large-sized, andhigh-definition liquid crystal panel. On the other hand, the liquidcrystal panel 100 of the embodiment has the multi-domain structure, butdoes not generate the changes of the width and shape of the dark linedue to the misalignment in the lateral direction (row direction).Because the liquid crystal panel 100 of the embodiment has the identicaldomain array in the lateral direction (row direction) so that the domainboundary and the dark line do not exist in the lateral direction, thisleads to an essential measure against the display unevenness in theliquid crystal panel 100 of the embodiment.

The generation situation of the display unevenness in the case that theliquid crystal panel 100 is bent will be described with reference to thedrawings.

FIGS. 20A and 20B are views each illustrating the case that the liquidcrystal panel 100 of the embodiment is bent, FIG. 20A illustrates thestate in which the liquid crystal panel 100 is not bent, and FIG. 20Billustrates the state in which the liquid crystal panel 100 is bent. Asillustrated in FIG. 20B, the display defect is not generated in any oneof a portion in which the misalignment of a first form is generated, aportion in which the misalignment is not generated, and a portion inwhich the misalignment of a second form is generated. FIGS. 21A and 21Bare views each illustrating the state of a dark line in a portion inwhich misalignment is not generated in the liquid crystal panel 100 ofthe embodiment, FIG. 21A is a plan view of the pixel, and FIG. 21B is across-sectional view taken along line A-A′. As illustrated in FIGS. 21Aand 21B, the dark line of a type A generated in a region where thealignment changes continuously due to an influence of the adjacentdomain having different alignment is generated in a domain boundaryregion. FIGS. 22A and 22B are views each illustrating the state of thedark line in a portion in which the misalignment of the first form isgenerated in the liquid crystal panel 100 of the embodiment, FIG. 22A isa plan view of the pixel, and FIG. 22B is a cross-sectional view takenalong line A-A′. As illustrated in FIGS. 22A and 22B, in the state inwhich the liquid crystal panel 100 is bent, for example, the TFTsubstrate is shifted onto the left side and the CF substrate is shiftedonto the right side, and the misalignment is generated. However, themisalignment in the lateral direction does not influence the liquidcrystal alignment, and the dark line of the type A is generated only inthe domain boundary region. FIGS. 23A and 23B are views eachillustrating the state of the dark line in a portion in which themisalignment of the second form is generated in the liquid crystal panel100 of the embodiment, FIG. 23A is a plan view of the pixel, and FIG.23B is a cross-sectional view taken along line A-A′. As illustrated inFIGS. 23A and 23B, the misalignment in the lateral direction does notinfluence the liquid crystal alignment, and the dark line of the type Ais generated only in the domain boundary region.

FIGS. 24A and 24B are views each illustrating the case that a firstconventional liquid crystal panel is bent, FIG. 24A illustrates thestate in which the first conventional liquid crystal panel is not bent,and FIG. 24B illustrates the state in which the first conventionalliquid crystal panel is bent. As illustrated in FIG. 24B, the displaydefect is generated in the portion in which the misalignment of thefirst form is generated and the portion in which the misalignment of thesecond form is generated. FIGS. 25A and 25B are views each illustratingthe state of the dark line in a portion in which the misalignment is notgenerated in the first conventional liquid crystal panel, FIG. 25A is aplan view of the pixel, and FIG. 25B is a cross-sectional view takenalong line A-A′. As illustrated in FIGS. 25A and 25B, the dark line ofthe type A is generated only in the domain boundary region. FIGS. 26Aand 26B are views each illustrating the state of the dark line in aportion in which the misalignment of the first form is generated in thefirst conventional liquid crystal panel, FIG. 26A is a plan view of thepixel, and FIG. 26B is a cross-sectional view taken along line A-A′. Asillustrated in FIGS. 26A and 26B, in a portion, in which the firstconventional liquid crystal panel is bent, and the TFT substrate isshifted onto the left side while the CF substrate is shifted onto theright side, thereby generating the misalignment of the first form, notonly the dark line of the type A is generated in the domain boundaryregion, but also the dark line of a type B generated in the region wherethe liquid crystal alignment becomes abnormal is generated bymismatching of the alignment controlling regions on the TFT substrateside and the CF substrate side due to the misalignment of the upper andlower substrates. As a result, luminance is degraded lower than theportion in which the misalignment is not generated. FIGS. 27A and 27Bare views each illustrating the state of the dark line in a portion inwhich the misalignment of the second form is generated in the firstconventional liquid crystal panel, FIG. 27A is a plan view of the pixel,and FIG. 27B is a cross-sectional view taken along line A-A′. Asillustrated in FIGS. 27A and 27B, in a portion, in which the firstconventional liquid crystal panel is bent, and the TFT substrate isshifted onto the right side while the CF substrate is shifted onto theleft side, thereby generating the misalignment of the second form, notonly the dark line of the type A is generated in the domain boundaryregion, but also the dark line of the type B generated in the regionwhere the liquid crystal alignment becomes abnormal is generated by themismatching of the alignment controlling regions on the TFT substrateside and the CF substrate side due to the misalignment of the upper andlower substrates. As a result, luminance is degraded lower than theportion in which the misalignment is not generated.

FIGS. 28A and 28B are views each illustrating the case that a secondconventional liquid crystal panel is bent, FIG. 28A illustrates thestate in which the second conventional liquid crystal panel is not bent,and FIG. 28B illustrates the state in which the second conventionalliquid crystal panel is bent. As illustrated in FIG. 28B, the displaydefect is generated in the portion in which the misalignment of thefirst form is generated and the portion in which the misalignment of thesecond form is generated. FIGS. 29A and 29B are views each illustratingthe state of the dark line in a portion in which the misalignment is notgenerated in the second conventional liquid crystal panel, FIG. 29A is aplan view of the pixel, and FIG. 29B is a cross-sectional view takenalong line A-A′. As illustrated in FIGS. 29A and 29B, the dark line ofthe type A is generated only in the domain boundary region. FIGS. 30Aand 30B are views each illustrating the state of the dark line in aportion in which the misalignment of the first form is generated in thesecond conventional liquid crystal panel, FIG. 30A is a plan view of thepixel, and FIG. 30B is a cross-sectional view taken along line A-A′. Asillustrated in FIGS. 30A and 30B, in a portion, in which the secondconventional liquid crystal panel is bent, and the TFT substrate isshifted onto the left side while the CF substrate is shifted onto theright side, thereby generating the misalignment of the first form, notonly the dark line of the type A is generated in the domain boundaryregion, but also the dark line of the type B generated in the regionwhere the liquid crystal alignment becomes abnormal is generated by themismatching of the alignment controlling regions on the TFT substrateside and the CF substrate side due to the misalignment of the upper andlower substrates. As a result, the dark line of the type A, which ishidden while overlapping the black matrix (light shielding body) in thestate in which the misalignment is not generated, appears outside thelight shielding body, and the luminance is degraded lower than theportion in which the misalignment is not generated. FIGS. 31A and 31Bare views each illustrating the state of the dark line in a portion inwhich the misalignment of the second form is generated in the secondconventional liquid crystal panel, FIG. 31A is a plan view of the pixel,and FIG. 31B is a cross-sectional view taken along line A-A′. Asillustrated in FIGS. 31A and 31B, in a portion, in which the secondconventional liquid crystal panel is bent, and the TFT substrate isshifted onto the right side while the CF substrate is shifted onto theleft side, thereby generating the misalignment of the second form, notonly the dark line of the type A is generated in the domain boundaryregion, but also the dark line of the type B generated in the regionwhere the liquid crystal alignment becomes abnormal is generated by themismatching of the alignment controlling regions on the TFT substrateside and the CF substrate side due to the misalignment of the upper andlower substrates. As a result, the dark line of the type A, which ishidden while overlapping the black matrix (light shielding body) in thestate in which the misalignment is not generated, appears outside thelight shielding body, and the luminance is degraded lower than theportion in which the misalignment is not generated.

FIGS. 32A and 32B are views each illustrating the case that a thirdconventional liquid crystal panel is bent, FIG. 32A illustrates thestate in which the third conventional liquid crystal panel is not bent,and FIG. 32B illustrates the state in which the third conventionalliquid crystal panel is bent. As illustrated in FIG. 32B, the displaydefect is generated in the portion in which the misalignment of thefirst form is generated and the portion in which the misalignment of thesecond form is generated. FIGS. 33A and 33B are views each illustratingthe state of the dark line in a portion in which the misalignment is notgenerated in the third conventional liquid crystal panel, FIG. 33A is aplan view of the pixel, and FIG. 33B is a cross-sectional view takenalong line A-A′. As illustrated in FIGS. 33A and 33B, the dark line ofthe type A is generated only in the domain boundary region. FIGS. 34Aand 34B are views each illustrating the state of the dark line in aportion in which the misalignment of the first form is generated in thethird conventional liquid crystal panel, FIG. 34A is a plan view of thepixel, and FIG. 34B is a cross-sectional view taken along line A-A′. Asillustrated in FIGS. 34A and 34B, in a portion, in which the thirdconventional liquid crystal panel is bent, and the TFT substrate isshifted onto the left side while the CF substrate is shifted onto theright side, thereby generating the misalignment of the first form, notonly the dark line of the type A is generated in the domain boundaryregion, but also the dark line of the type B generated in the regionwhere the liquid crystal alignment becomes abnormal is generated by themismatching of the alignment controlling regions on the TFT substrateside and the CF substrate side due to the misalignment of the upper andlower substrates. As a result, the dark line of the type A, which ishidden while overlapping the black matrix (light shielding body) in thestate in which the misalignment is not generated, appears outside thelight shielding body. Because the dark line of the type A appears in thepixel having a specific color, a color shift is generated as comparedwith the portion in which the misalignment is not generated. FIGS. 35Aand 35B are views each illustrating the state of the dark line in aportion in which the misalignment of the second form is generated in thethird conventional liquid crystal panel, FIG. 35A is a plan view of thepixel, and FIG. 35B is a cross-sectional view taken along line A-A′. Asillustrated in FIGS. 35A and 35B, in a portion, in which the thirdconventional liquid crystal panel is bent, and the TFT substrate isshifted onto the right side while the CF substrate is shifted onto theleft side, thereby generating the misalignment of the second form, notonly the dark line of the type A is generated in the domain boundaryregion, but also the dark line of the type B generated in the regionwhere the liquid crystal alignment becomes abnormal is generated by themismatching of the alignment controlling regions on the TFT substrateside and the CF substrate side due to the misalignment of the upper andlower substrates. As a result, the dark line of the type A, which ishidden while overlapping the black matrix (light shielding body) in thestate in which the misalignment is not generated, appears outside thelight shielding body. Because the dark line of the type A appears in thepixel having a specific color, a color shift is generated as comparedwith the portion in which the misalignment is not generated.

An outline of the configuration of the liquid crystal display device ofthe embodiment will be described below. The first substrate 30 is anactive matrix substrate (TFT substrate), and the active matrix substratethat is commonly used in the field of the liquid crystal panel can beused as the first substrate 30. FIG. 4 is a schematic plan viewillustrating the oblique azimuth of the liquid crystal molecules 41 inthe liquid crystal layer 40 while the oblique azimuth is superposed onan example of an electrode and line structure of the first substrate 30of the embodiment. A configuration in which multiple gate lines Gparallel to each other; multiple source lines S that extend in adirection orthogonal to the gate line G and are formed in parallel toeach other; an active element such as a TFT 13 disposed at anintersection of the gate line G and the source line S; multiple drainlines D disposed in the region sectioned by the gate line G and thesource line S; and the pixel electrodes 35 are provided on a transparentsubstrate 31 in a plan view of the first substrate 30. A capacitanceline Cs may be disposed in parallel to the gate line G. In the crosssection of the first substrate 30, an insulating film 32 such as a gateinsulating film and an interlayer insulating film is provided betweenthe gate line G and the pixel electrode 35.

A TFT in which a channel is formed using an oxide semiconductor issuitably used as the TFT 13. Examples of the oxide semiconductorsinclude a compound (In—Ga—Zn—O) containing indium (In), gallium (Ga),zinc (Zn), and oxygen (O), a compound (In—Sn—Zn—O) containing indium(In), tin (Sn), zinc (Zn), and oxygen (O), and a compound (In—Al—Zn—O)containing indium (In), aluminum (Al), zinc (Zn), and oxygen (O).

The pixel electrode 35 is preferably made of a transparent conductivematerial. Examples of the transparent conductive materials includeindium tin oxide (ITO) and indium zinc oxide (IZO).

Each of the pixel electrodes 35 is superimposed on the first domain 10a, the second domain 10 b, the third domain 10 c, and the fourth domain10 d. Thus, when the voltage is applied to the liquid crystal layer 40,an electric field having the same magnitude is applied in a thicknessdirection of the liquid crystal layer 40 in the first domain 10 a, thesecond domain 10 b, the third domain 10 c, and the fourth domain 10 d.

The pixel electrode 35 includes a first pixel electrode 35A having aconfiguration in which a fine slit 36 parallel to the alignment vectorof the corresponding domain is provided in at least one of a regionsuperimposed on the first domain 10 a, a region superimposed on thesecond domain 10 b, a region superimposed on the third domain 10 c, or aregion superimposed on the fourth domain 10 d while the fine slit 36 isnot provided in the remaining region. As used herein, the fine slitmeans multiple pairs in each of which the slit and electrode extendingin a direction parallel to the desired alignment direction (alignmentvector) of the liquid crystal are paired. The fine slit 36 generateselectric field distortion having a groove-shaped equipotential surfaceparallel to the extending direction of the slit portion. The electricfield formed by the fine slit 36 has a lateral electric field componentparallel to the substrate surface and perpendicular to the extendingdirection of the slit portion. The alignment direction of the liquidcrystal molecules 41 changes due to the lateral electric fieldcomponent, and the liquid crystal molecules 41 are aligned in parallelto the slit.

Preferably a width (space) and a pitch (line+space) of the fine slit 36satisfy the following conditions.

width (space) of fine slit 36≤5.1 μm

pitch (line+space) of fine slit 36≤11 μm

More preferably a width (space) and a pitch (line+space) of the fineslit 36 satisfy the following conditions.

width (space) of the fine slit 36≤4.3 μm

pitch (line+space) of fine slit 36≤8.3 μm

In the pixel electrode 35, preferably the fine slits 36 are not providedat both ends in the column direction. That is, as illustrated in FIG. 4,linear electrode portions sectioned by the slits of the fine slits 36are electrically connected to each other by connection portion (solidelectrode) at both ends in the column direction.

Preferably the fine slits 36 are not provided up to the end of the pixelelectrode 35. Although the fine slits 36 have advantage of improving thealignment controlling force to enhance a response speed, the fine slits36 have disadvantage of generating a line width variation due toreduction in production efficiency or unevenness of scanning exposure,so that the arrangement region of the fine slits 36 may be limited. Forexample, the arrangement patterns of the fine slits 36 may be thoseillustrated in FIGS. 18A to 18E, 19A, and 19B. As illustrated in FIGS.18A to 18E, 19A, and 19B, a slit (hereinafter also referred to as“center slit”) 37 may be disposed at the boundary between the seconddomain 10 b and the third domain 10 c. Because an angle differencebetween the alignment vectors of the domains adjacent to each other is180° at the boundary between the second domain 10 b and the third domain10 c, the liquid crystal molecules 41 can hardly be aligned in theintended direction, and the linear dark portion (dark line) throughwhich the light is insufficiently transmitted is easily generated duringthe display. For this reason, the center slit 37 is disposed to generatethe electric field distortion, which allows the suppression of the darkline. The width of the center slit 37 ranges preferably from 1 μm to 8μm, more preferably from 2.5 μm to 6 μm.

As illustrated in FIG. 4, preferably the first pixel electrode 35A has aconfiguration in which the fine slit 36 is provided in two of the regionsuperimposed on the first domain 10 a, the region superimposed on thesecond domain 10 b, the region superimposed on the third domain 10 c,and the region superimposed on the fourth domain 10 d while the fineslit 36 is not provided in the remaining two regions.

In the first substrate 30, the pixel electrode 35 is disposed in eachpixel 10. The fine slit 36 may be disposed in different regions of eachpixel electrode 35. The pixel electrode 35 preferably includes at leastone of the following combinations (1) to (4).

(1) a combination of the pixel electrode in which the fine slit 36 isprovided in the region superimposed on the first domain 10 a and thepixel electrode in which the fine slit 36 is not provided in the regionsuperimposed on the first domain 10 a

(2) a combination of the pixel electrode in which the fine slit 36 isprovided in the region superimposed on the second domain 10 b and thepixel electrode in which the fine slit 36 is not provided in the regionsuperimposed on the second domain 10 b

(3) a combination of the pixel electrode in which the fine slit 36 isprovided in the region superimposed on the third domain 10 c and thepixel electrode in which the fine slit 36 is not provided in the regionsuperimposed on the third domain 10 c

(4) a combination of the pixel electrode in which the fine slit 36 isprovided in the region superimposed on the fourth domain 10 d and thepixel electrode in which the fine slit 36 is not provided in the regionsuperimposed on the fourth domain 10 d

As illustrated in FIG. 4, preferably the pixel electrode 35 includessecond pixel electrodes 35B and 35C. The second pixel electrodes 35B and35C are disposed adjacent to the first pixel electrode 35A, and have aconfiguration in which the fine slit 36 is provided in two regionssuperimposed on two types of domains (the second domain 10 b and thethird domain 10 c) in which the fine slit 36 is not provided in thefirst pixel electrode 35A while the fine slit 36 is not provided in theremaining two regions. The second pixel electrode 35B is disposedadjacent to the first pixel electrode 35A in the column direction. Thesecond pixel electrode 35C is disposed adjacent to the first pixelelectrode 35A in the row direction.

A combination of the first pixel electrode 35A having the configurationin which the fine slit 36 is provided in the region superimposed on thefirst domain 10 a and the region superimposed on the fourth domain 10 dwhile the fine slit 36 is not provided in the region superimposed on thesecond domain 10 b and the region superimposed on the third domain 10 cand the second pixel electrodes 35B and 35C having the configuration inwhich the fine slit 36 is provided in the region superimposed on thesecond domain 10 b and the region superimposed on the third domain 10 cwhile the fine slit 36 is not provided in the region superimposed on thefirst domain 10 a and the region superimposed on the fourth domain 10 dcan be cited as a preferred combination of the first pixel electrode 35Aand the second pixel electrodes 35B and 35C.

The color filter substrate (CF substrate) can be used as the secondsubstrate 50. A configuration in which the black matrix formed into alattice shape and a lattice, namely, the color filter formed inside thepixel 10 are provided on the transparent substrate can be cited as theconfiguration of the color filter substrate. The black matrix may beformed into the lattice shape in each pixel so as to overlap theboundary of the pixel 10, or formed into the lattice shape in each halfpixel so as to cross the center of one pixel along the short-sidedirection. When the black matrix is formed so as to overlap the regionwhere dark line is generated, the dark line is hardly observed, and theinfluence of the dark line on the display can be minimized.

The counter electrode 51 is disposed so as to be opposed to the pixelelectrode 35 with the liquid crystal layer 40 interposed therebetween.The vertical electric field is formed between the counter electrode 51and the pixel electrode 35 and the liquid crystal molecules 41 areinclined, which allows the display to be performed. For example, in eachcolumn, the color filters may be arranged in the order of red (R), green(G), and blue (B), in the order of yellow (Y), red (R), green (G), andblue (B), or in the order of red (R), green (G), blue (B), and green(G).

Preferably the counter electrode 51 is a planar electrode. The counterelectrode 51 may be a transparent electrode. For example, the counterelectrode 51 can be made of a transparent conductive material such asindium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), andtin oxide (SnO) or an alloy thereof.

In the liquid crystal panel 100 of the embodiment, the first substrate30 and the second substrate 50 are bonded together by the sealingmaterial 80 that is provided so as to surround the liquid crystal layer40, and the liquid crystal layer 40 is held in a predetermined region.For example, an epoxy resin containing an inorganic filler or an organicfiller and a hardener can be used as the sealing material 80.

A polymer sustained alignment (PSA) technique may be used in theembodiment. In the PSA technique, a liquid crystal compositioncontaining a photopolymerizable monomer is filled between the firstsubstrate 30 and the second substrate 50, the liquid crystal layer 40 isirradiated with light to polymerize the photopolymerizable monomer, apolymer is formed on the surfaces of the first alignment film 71 and thesecond alignment film 72, and the initial inclination (pre-tilt) of theliquid crystal is fixed by the polymer.

As illustrated in FIG. 2, a polarization axis of the back-sidepolarizing plate 20 and a polarization axis of the display-sidepolarizing plate 60 may be orthogonal to each other. The polarizationaxis may be an absorption axis or a transmission axis of the polarizingplate. Typically, the back-side polarizing plate 20 and the display-sidepolarizing plate 60 are those obtained by adsorbing and aligning ananisotropic material such as a dichroic iodine complex onto a polyvinylalcohol (PVA) film. Usually, a protective film such as a triacetylcellulose film is laminated on both sides of the PVA film, and put intopractical use. An optical film such as a retardation film may bedisposed between the back-side polarizing plate 20 and the firstsubstrate 30 and between the display-side polarizing plate 60 and thesecond substrate 50.

Any backlight that emits the light including visible light, anybacklight that emits the light including only the visible light, or anybacklight that emits the light including both the visible light andultraviolet light may be used as the backlight 110. A backlight thatemits white light is suitably used in order to perform color display onthe liquid crystal display device. For example, a light emitting diode(LED) is suitably used as a type of the backlight 110. As used herein,the term “visible light” means light (electromagnetic wave) having awavelength that is greater than or equal to 380 nm and less than 800 nm.

In addition to the liquid crystal panel 100 and the backlight 110, theliquid crystal display device of the embodiment includes an externalcircuit such as a tape-carrier package (TCP) and a printed circuit board(PCB); an optical film such as a viewing angle increasing film and aluminance improving film; and a bezel (frame). Some components may beincorporated into another component. Components other than thosedescribed above are not particularly limited and are not described herebecause such components can be those commonly used in the field ofliquid crystal display devices.

A method of manufacturing the liquid crystal panel 100 of the embodimentwill be described below. The method of manufacturing the liquid crystalpanel 100 of the embodiment is not particularly limited, but a methodusually used in the field of the liquid crystal panel can be adopted.The gate line G and the pixel electrode 35 that are provided on thefirst substrate 30 and the color filter provided on the second substrate50 can be formed by photolithography.

From the viewpoints of patterning accuracy and productivity, thephotolithography is suitably used as the method of forming the pixelelectrode 35 having the fine slits 36. In the case that the fine slits36 are formed by the photolithography, a photosensitive resin(photoresist) formed on the conductive film that constitutes a materialof the pixel electrode 35 is irradiated with light through a mask havinga pattern corresponding to the fine slits 36. The photoresist may beirradiated with the light through multiple lenses (multi-lens).

The case that the photoresist is irradiated with the light used for thepatterning of the fine slits 36 through the multi-lens will be describedwith reference to the drawings. FIG. 5 is a view illustratingphotolithography using a multi-lens; As illustrated in FIG. 5, exposureis performed on a substrate 170 through a mask 150 including a patternformation region 151 where a light shielding pattern or a lighttransmitting pattern corresponding to the fine slit 36 is formed and amulti-lens 160 including the lenses. A substrate on which a photoresist172 is formed on a conductive film 171 that constitutes the material ofthe pixel electrode 35 is used as the substrate 170. An exposure systemis preferably scanning exposure that is performed while at least one ofan exposure unit including the mask 150 and the multi-lens 160 or thesubstrate 170 is moved. Development of the photoresist 172, etching ofthe conductive film 171, and peeling of the photoresist 172 aresequentially performed after the exposure.

When the exposure is performed using the multi-lens 160, a focal pointor illuminance of each lens may vary. FIG. 6A is a schematiccross-sectional view illustrating an arrangement relation of lenses160A, 160B, 160C, 160D, 160E in the multi-lens 160, and FIG. 6B is aconceptual view illustrating a pattern of the luminance unevennessgenerated when the pixel electrode 35 including fine slits 36 is formedby scanning exposure in which the multi-lens 160 in FIG. 6A is used. Inthe case that a difference in the focal point or illuminance existsamong the lenses 160A, 160B, 160C, 160D, 160E when the scanning exposureis performed with the arrangement of the lenses 160A, 160B, 160C, 160D,160E in FIG. 6A, the line width of the fine slits 36 varies in exposureregions 172A, 172B, 172C, 172D, 172E corresponding to the lenses 160A,160B, 160C, 160D, 160E as illustrated in FIG. 6B. As a result, theluminance of the liquid crystal panel 100 varies in each of the exposureregions 172A, 172B, 172C, 172D, 172E, and is sometimes recognized as thedisplay unevenness. In particular, because the boundary between theadjacent exposure regions 172A, 172B, 172C, 172D, 172E is a portion inwhich the line width of the fine slits 36 changes, the boundary isrecognized as seam-shaped display unevenness to degrade the displayquality of the liquid crystal panel 100.

On the other hand, in the liquid crystal panel 100 of the embodiment,the region (also referred to as a “fine slit region”) where the fineslit 36 parallel to the alignment vector of the corresponding domain isprovided and the region (also referred to as a “solid region”) where thefine slit 36 is not provided are provided in the pixel electrode 35. Byproviding the solid region, the boundary between the regions havingdifferent line widths of the fine slits 36 can be prevented fromcontinuing linearly, and hardly recognized as seam-shaped displayunevenness.

The fine slit region and the solid region are different from each otherin luminance (transmittance) obtained with respect to the voltage (thegray scale of the liquid crystal display) applied to the pixel electrode35. FIG. 7 is a graph illustrating a relationship between the gray scaleof the liquid crystal display in the liquid crystal panel 100 of theembodiment and transmittance with respect to each of the fine slitregion, the solid region, and a total of the fine slit region and thesolid region. As illustrated in FIG. 7, the transmittance of the fineslit region is higher than that of the solid region at the maximum grayscale (around a gray scale value of 255), but the transmittance of thesolid region is higher than the transmittance of the fine slit region atthe low gray scale (around a gray scale value of 16). FIG. 8 is a graphillustrating a ratio (fine slit contribution ratio) of the transmittanceof the fine slit region to the total of the transmittances of the fineslit region and the solid region for each gray scale value of the liquidcrystal display. Because the solid region has the higher transmittancethan that of the fine slit region at the low gray scale, the ratio ofthe transmittance of the fine slit region becomes about 10% at the lowgray scale as illustrated in FIG. 8. As a result, even if transmittanceunevenness (luminance unevenness) is generated in each domain due to thevariation in the line width of the fine slit, the transmittanceunevenness is not conspicuous particularly at the low gray scale.According to the study by the inventors, it is found that the change intransmittance caused by the variation in the line width of the fine slitis notable particularly at the low gray scale in the display mode of theliquid crystal panel 100 of the embodiment. Thus, when the fine slitregion and the solid region are mixed, the luminance unevenness at thelow gray scale can effectively be prevented.

In the liquid crystal panel 100 of the embodiment, because the pluralityof pixels 10 each of which includes four domains 10 a, 10 b, 10 c, and10 d having different alignment vectors are provided, the displayunevenness can be prevented from having viewing angle dependency byproviding the fine slit region and the solid region in each domain. Thatis, the pixel electrode (first pixel electrode 35A) in which the fineslit 36 is provided in the region superimposed on the first domain 10 aand the pixel electrode (second pixel electrodes 35B and 35C) in whichthe fine slit 36 is not provided in the region superimposed on the firstdomain 10 a are combined and disposed, which allows the luminance asviewed from the first direction to be prevented from being differentfrom the luminance as viewed from another direction. Similarly, thepixel electrode (second pixel electrodes 35B and 35C) in which the fineslit 36 is provided in the region superimposed on the second domain 10 band the pixel electrode (first pixel electrode 35A) in which the fineslit 36 is not provided in the region superimposed on the second domain10 b are combined and disposed, which allows the luminance as viewedfrom the second direction to be prevented from being different from theluminance as viewed from another direction. The pixel electrode (secondpixel electrodes 35B and 35C) in which the fine slit 36 is provided inthe region superimposed on the third domain 10 c and the pixel electrode(first pixel electrode 35A) in which the fine slit 36 is not provided inthe region superimposed on the third domain 10 c are combined anddisposed, which allows the luminance as viewed from the third directionto be prevented from being different from the luminance as viewed fromanother direction. The pixel electrode (first pixel electrode 35A) inwhich the fine slit 36 is provided in the region superimposed on thefourth domain 10 d and the pixel electrode (second pixel electrodes 35Band 35C) in which the fine slit 36 is not provided in the regionsuperimposed on the fourth domain 10 d are combined and disposed, whichallows the luminance as viewed from the fourth direction to be preventedfrom being different from the luminance as viewed from anotherdirection.

When the first pixel electrode 35A and the second pixel electrodes 35Band 35C are used in combination with each other, a set of the fine slitregion and the solid region corresponding to the same type of domain areprovided in two pixels adjacent to each other, so that the displayunevenness having the viewing angle dependency can more effectively beprevented.

In the liquid crystal panel 100 of the embodiment, a repeating unit ofthe domain array is not one line (four domains) but two lines (eightdomains) by varying the domain array in the nth row pixel and the domainarray in the (n+1)th row pixel. This also exerts the effect that theboundaries of the exposure regions 172A, 172B, 172C, 172D, 172E arehardly recognized as the seam-shaped display unevenness as compared witha general form in which the domain array of each row is the same.

A photo alignment film can also be used for one or both of the firstalignment film 71 and the second alignment film 72. In this case, thealignment treatment performed on the photo alignment film can beperformed by the photo alignment treatment in which the photo alignmentfilm is irradiated with light (electromagnetic wave) such as ultravioletlight and visible light. For example, the photo alignment treatment isperformed using a device, which includes a light source that emits thelight to the first alignment film 71 and the second alignment film 72and has a function of performing continuous scanning exposure over thepixels. Examples of specific modes of the scanning exposure include amode in which a substrate surface is irradiated with the light emittedfrom the light source while the substrate is moved, a mode in which thesubstrate surface is irradiated with the light emitted from the lightsource while the light source is moved, and a mode in which thesubstrate surface is irradiated with the light emitted from the lightsource while the light source and the substrate are moved.

A specific example of the alignment treatment will be described below.FIG. 9 is a schematic diagram illustrating an example of the photoalignment treatment device. A photo alignment treatment device 200 inFIG. 9 performs the photo alignment treatment on the photo alignmentfilm formed on the liquid crystal panel substrate. Although the firstalignment film 71 formed on the first substrate (liquid crystal panelsubstrate) 30 is illustrated in FIG. 9, the second alignment film 72 canalso be processed. The photo alignment treatment device 200 includes alight irradiation mechanism 280 and a stage 250 on which the liquidcrystal panel substrate 30 is placed.

The light irradiation mechanism 280 includes a light source 220, apolarizer 230, and a rotation adjustment mechanism 260. The light source220 and the polarizer 230 may be disposed in a lamp box 270. A type ofthe light source 220 is not particularly limited, but a light sourcetypically used in the field of the photo alignment treatment device canbe used. For example, a low-pressure mercury lamp, a deuterium lamp, ametal halide lamp, an argon resonance lamp, and a xenon lamp can beused.

Light 221 emitted from the light source 220 may be light(electromagnetic wave) such as ultraviolet light and visible light, andthe light 221 preferably has a wavelength of 280 nm to 400 nm.

For example, the polarizer 230 extracts linearly polarized light fromthe light emitted from the light source 220 toward the liquid crystalpanel substrate 30. The polarization axis means to transmission axis oran absorption axis of the polarizer. Examples of the polarizer 230include an organic resin polarizer, a wire grid polarizer, and apolarizing beam splitter (PBS).

A polarizer obtained by adsorbing iodine in polyvinyl alcohol andextending polyvinyl alcohol in a sheet shape can be cited as an exampleof the organic resin polarizer.

For example, the wire grid polarizer includes a light transmission basematerial and multiple metal thin wires formed on the light transmissionbase material, and the metal thin wires are disposed in a period shorterthan the wavelength of light incident on the wire grid polarizer. Themetal thin wire is made of a light absorbing metal material such aschromium. When the wire grid polarizer is irradiated with the lightwhile superimposed on the liquid crystal panel substrate 30, the liquidcrystal molecules are aligned in the azimuth orthogonal to an extendingazimuth of the metal thin wire. In the case that the polarizer 230 isthe wire grid polarizer, the polarization axis is the azimuth orthogonalto the extending azimuth of the metal thin wire. Alignment divisiontreatment can efficiently be performed using the wire grid polarizerhaving a different extending azimuth of the metal thin wire.

A cube type polarization beam splitter or a plate type polarization beamsplitter can be cited as an example of the polarization beam splitter. APBS, in which slopes of two prisms are bonded together and an opticalthin film is evaporated on one of the slopes, can be cited as an exampleof the cube type PBS.

The polarizer 230 may be disposed perpendicular to the light irradiationaxis. In the case that the polarizer 230 is not disposed perpendicularlyto the light irradiation axis, sometimes the alignment of the liquidcrystal molecules is influenced by a waveguide effect in the polarizer230. The light irradiation axis is a direction in which the light 221emitted from the light source 220 toward the liquid crystal panelsubstrate 30 propagates linearly. The disposition of the polarizerperpendicular to the light irradiation axis means that the polarizer isdisposed such that the light is emitted from a normal direction of thepolarizer toward the liquid crystal panel substrate, and the term“perpendicular” means a range in which an angle formed between thenormal line of the polarizer and the light irradiation axis is less than0.5°.

A wavelength selection filter 235 may be included between the lightsource 220 and the polarizer 230. A main wavelength of the light emittedthrough the wavelength selection filter 235 may range from 280 nm to 400nm. The selection wavelength of 280 nm to 400 nm can generate astructural change of a material, which constitutes the first alignmentfilm 71 and exhibits the photo alignment characteristic, and exert thealignment controlling force. Intensity of the light emitted from thelight source may range from 10 mJ/cm² to 100 mJ/cm².

The wavelength selection filter 235 is not particularly limited, and awavelength selection filter typically used in the field of the photoalignment treatment device can be used. A wavelength selection filter inwhich a substance absorbing a wavelength other than the transmissionwavelength is dispersed in the filter or a wavelength selection filterin which a substance reflecting a wavelength other than the transmissionwavelength is coated on the surface of the filter can be cited as anexample of the wavelength selection filter 235.

The light irradiation angle with respect to the liquid crystal panelsubstrate 30 may range from 30° to 60°. The irradiation angle isrepresented by θ1 in FIG. 13, and is an angle formed between a plane ofthe liquid crystal panel substrate 30 and the light irradiation axis inthe case that the surface of the liquid crystal panel substrate 30 isset to 0° and in the case that the normal line of the liquid crystalpanel substrate 30 is set to 90°.

An extinction ratio of the polarizer may range from 50:1 to 500:1. Theextinction ratio is represented by Tmax:Tmin, where Tmax is maximumtransmittance in the case that the polarizer is irradiated with thelight and Tmin is minimum transmittance obtained by rotating thepolarizer by 90°. The light in the desired polarization axis directionis taken out with increasing extinction ratio (a value of Tmax in thecase that Tmin is set to 1), so that a variation in oblique azimuth ofthe liquid crystal molecules can be reduced.

The rotation adjustment mechanism 260 rotates a polarization axis 231 ofthe polarizer 230, and adjusts an exposure direction 253 on the surfaceof the liquid crystal panel substrate 30 so as to substantially become45° with respect to a light irradiation direction 252. By setting theexposure direction 253 to substantially 45° with respect to the lightirradiation direction 252, the photo alignment treatment can beperformed on the liquid crystal panel substrate 30 by scanning exposurehaving excellent productivity while a movement direction 251 of theliquid crystal panel substrate 30 is kept in parallel to the lightirradiation direction 252. As illustrated in FIG. 9, the lightirradiation direction 252 means a light traveling direction in the casethat the light 221 emitted from the light source 220 is projected ontothe surface of the liquid crystal panel substrate 30. The exposuredirection 253 means a vibration direction of polarized light emittedfrom the light source 220 to the surface of the liquid crystal panelsubstrate 30 through the polarizer 230. A pre-tilt azimuth that thealignment film formed on the surface of the liquid crystal panelsubstrate 30 provides to the liquid crystal molecules is fixed by theexposure direction 253.

For example, the polarization axis 231 is adjusted using the rotationadjustment mechanism 260 by the following method. The polarizer 230 isset such that the polarization axis 231 becomes 45° with respect to thelight irradiation direction 252. The azimuth of the polarization axisbefore the polarization axis is adjusted by the rotation adjustmentmechanism is also referred to as “a 45° azimuth”. Subsequently, therotation adjustment mechanism 260 rotates the polarizer 230 from the 45°azimuth to adjust the azimuth of the polarization axis 231 based on datacalculated by geometric computation in consideration of the lightirradiation angle with respect to the liquid crystal panel substrate anda refractive index of the alignment film material. The rotationadjustment mechanism 260 can match the azimuth of the polarization axisof the polarizer with respect to the light irradiation direction withthe exposure direction on the surface of the liquid crystal panelsubstrate to set the oblique azimuth of the liquid crystal molecules inthe liquid crystal panel to a desired angle. When the photo alignmenttreatment is performed with no use of the rotation adjustment mechanism260 while the polarization axis 231 is fixed to the 45° azimuth,sometimes the oblique azimuth of the liquid crystal molecules deviatesby about 10° from about 45°.

The rotation adjustment mechanism 260 may rotate the polarization axisof the polarizer 230 in the range of −15° to +15° from the 45° azimuth.When the rotation adjustment mechanism 260 rotates the polarization axisin the range of −15° to +15°, even if the light irradiation angle ischanged with respect to the liquid crystal panel substrate 30, theexposure direction 253 can be adjusted to set the oblique azimuth of theliquid crystal molecules to the desired angle. For example, thepolarization axis 231 is rotated from the 45° azimuth by +7.55° and setto 52.55° in order to adjust the exposure direction 253 on the surfaceof the liquid crystal panel substrate to substantial 45° with respect tothe light irradiation direction 252.

The photo alignment treatment device 200 may further include a rotationmechanism 264. The rotation mechanism 264 can rotate the polarizationaxis 231 of the polarizer 230 by selecting either substantial 45° orsubstantial 90° from the 45° azimuth. In the case that the azimuth of45° is set to the +45° azimuth clockwise with respect to the lightirradiation direction 252, the rotated polarization axis 231 becomes the−45° azimuth with respect to the light irradiation direction 252 whenthe polarization axis 231 of the polarizer 230 is rotated by 90° fromthe +45° azimuth. The polarization axis 231 is rotated by 90° from the+45° azimuth and adjusted by the rotation adjustment mechanism 260,which allows the light irradiation to be performed while the exposuredirection 253 is set to substantial 45° with respect to the lightirradiation direction 252 before and after the rotation. Consequently,the embodiment is suitable for manufacturing a liquid crystal panelhaving an alignment control mode, in which four alignment regions havingmutually different oblique azimuths of the liquid crystal molecules arearranged along a longitudinal direction of the pixel as illustrated inFIG. 2. The liquid crystal panel having the new alignment control modecan be manufactured by the scanning exposure, so that productionefficiency can greatly be improved. The term “substantial 45° orsubstantial 90° from the 45° azimuth” means a range of an angle of 15°clockwise or counterclockwise from 45° or 90° with respect to the 45°azimuth, respectively. The 45° azimuth and the 90° azimuth refer to arange of ±0.5° from 45° and 90°, respectively.

The rotation mechanism 264 can also rotate the polarization axis 231 ofthe polarizer 230 from the 45° azimuth to substantial 45°. When thepolarization axis 231 is rotated by 45° from the 45° azimuth, therotated polarization axis 231 is parallel to the light irradiationdirection, so that the conventional photo alignment treatment in whichthe polarization axis of the polarizer is matched with the lightirradiation direction can also be performed.

The stage 250 is a stage on which the liquid crystal panel substrate 30is placed. The liquid crystal panel substrate 30 is fixed onto the stage250, and the liquid crystal panel substrate 30 is irradiated with thelight while the liquid crystal panel substrate 30 is moved, or theliquid crystal panel substrate 30 is irradiated with the light while thelight source is moved with respect to the liquid crystal panel substrate30. The photo alignment treatment can efficiently be performed byperforming the scanning exposure. The light irradiation direction withrespect to the liquid crystal panel substrate 30 is parallel to themovement direction of the liquid crystal panel substrate 30 or themovement direction of the light source 220, and an incident angle oflight incident on the substrate from the light source becomessubstantially the same in a light irradiation area of the light source,so that a pre-tilt angle (polar angle) provided to the liquid crystalmolecules also becomes substantially the same. For this reason, avariation in pre-tilt angle can be suppressed in the light irradiationarea to manufacture the liquid crystal panel having excellent displayquality. The photo alignment treatment device 200 may include a stagescanning mechanism that moves the stage 250 and/or a light sourcescanning mechanism that moves the light source 220. The term “parallel”includes a range in which the angle formed between the light irradiationdirection and the movement direction of the liquid crystal panelsubstrate 30 or the movement direction of the light source 220 is lessthan 5°.

The photo alignment treatment device 200 may include a light shieldingmember 240 in addition to the stage scanning mechanism and/or the lightsource scanning mechanism. The alignment division treatment can beperformed by performing the photo alignment treatment while a portionthat is not irradiated with the light is shielded by the light shieldingmember 240.

The use of the photo alignment treatment device can match the azimuth ofthe polarization axis of the polarizer with respect to the lightirradiation direction with the exposure direction on the surface of theliquid crystal panel substrate to set the oblique azimuth of the liquidcrystal molecules 41 in the liquid crystal panel 100 to the desiredangle.

An example of a photo alignment treatment step using the photo alignmenttreatment device 200 will be described below with reference to FIG. 14.FIG. 10 is a view illustrating an example of the photo alignmenttreatment step using the photo alignment treatment device. The photoalignment treatment step in FIG. 10 is an example in which, using thelight irradiation mechanism 280 including one polarizer 230, thepolarization axis 231 of the polarizer 230 is rotated by the rotationmechanism 264 to perform the photo alignment treatment. In FIG. 10, inorder to describe the azimuth of the liquid crystal panel substrate 30,a notch is illustrated in one corner. However, the actual liquid crystalpanel substrate 30 may not include the notch.

As illustrated in FIG. 10, the movement direction 251 of the liquidcrystal panel substrate 30 is set to the first direction, the lightirradiation direction 252 is set to the second direction, and thefirst-time light irradiation is performed through the wavelengthselection filter 235 (not illustrated) and the polarizer 230 using thelight irradiation mechanism 280. The first direction and the seconddirection are parallel to each other. The region that is not irradiatedwith the light is shielded by the light shielding member 240. Thepolarization axis 231 of the polarizer 230 is set to the +45° azimuthclockwise with respect to the light irradiation direction 252, and thenthe rotation adjustment mechanism 260 adjusts the exposure direction 253on the surface of the liquid crystal panel substrate 30 to substantial45° with respect to the light irradiation direction 252 to perform thefirst-time light irradiation. Subsequently, the light shielding member240 is moved, the polarization axis 231 of the polarizer 230 is rotatedby 90° from the +45° azimuth by the rotation mechanism 264 and set tothe −45° azimuth counterclockwise with respect to the light irradiationdirection 252, and then the polarization axis 231 is adjusted by therotation adjustment mechanism 260 to perform the second-time lightirradiation. Subsequently, the substrate is rotated by 180°, the lightshielding member 240 is further moved, the polarizer 230 is rotated by90° from the −45° azimuth by the rotation mechanism 264 and set to the+45° azimuth, and then the polarization axis 231 is adjusted by therotation adjustment mechanism 260 to perform the third-time lightirradiation. Finally, the light shielding member 240 is moved, thepolarizer 230 is rotated by 90° from the +45° azimuth by the rotationmechanism 264 and set to the −45° azimuth, and then the polarizationaxis 231 is adjusted by the rotation adjustment mechanism 260 to performthe fourth-time light irradiation. In the liquid crystal panel substrate30 subjected to the light irradiation step, a pre-tilt azimuth 253varies in each of regions corresponding to the four alignment regionsformed in one pixel. The movement direction 251 and the lightirradiation direction 252 of the liquid crystal panel substrate 30 arethe same in all the first-time light irradiation to the fourth-timelight irradiation. In all the first-time light irradiation to thefourth-time light irradiation, the polarization axis 231 is adjusted bythe rotation adjustment mechanism 260 such that the exposure direction253 on the surface of the liquid crystal panel substrate 30 becomessubstantial 45° with respect to the light irradiation direction 252.

FIG. 11A is a view illustrating the photo alignment treatment performedon the TFT substrate (first substrate), FIG. 11B is a view illustratingthe photo alignment treatment performed on the CF substrate (secondsubstrate), and FIG. 11C is a view illustrating a state after bonding ofthe TFT substrate and the CF substrate that are subject to the photoalignment treatment; As illustrated in FIG. 11A, the TFT substrate(first substrate) 30 is subjected to the photo alignment treatment bychanging the pre-tilt azimuth 253 in each domain by the first-time lightirradiation to the fourth-time light irradiation. In the same manner asin the TFT substrate, as illustrated in FIG. 11B, the CF substrate(second substrate) 50 is also subjected to the photo alignment treatmentby changing a pre-tilt azimuth 254 in each domain by the first-timelight irradiation to the fourth-time light irradiation. As illustratedin FIGS. 11A and 11B, the first domain 10 a, the second domain 10 b, thethird domain 10 c, and the fourth domain 10 d that are included in theliquid crystal panel 100 of the embodiment are completed when the TFTsubstrate 30 and the CF substrate 50 that are subjected to the photoalignment treatment are bonded together.

(Modifications)

The arrangement relation between the domain array and the fine slitsprovided in the pixel electrode 35 may be those in FIGS. 12 to 18. FIG.12 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules 41 in the liquid crystal layer 40 while theoblique azimuth is superposed on an example of the electrode and linestructure of the first substrate 30 according to a first modification.In the pixel electrode 35 of the first modification, the fine slit 36 isprovided in the two regions located at the second and third positionsfrom one electrode end among the regions superimposed on the fourdomains, and the fine slit 36 is not provided in the two regions locatedat the first and fourth positions. In relation to the line, the fineslit 36 is provided in the domain located along the capacitance line Cs.In relation to the domain, the pixel electrode 35 of the firstmodification includes a first pixel electrode 35D having a configurationin which the fine slit 36 is provided in the region superimposed on thesecond domain 10 b and the region superimposed on the third domain 10 cwhile the fine slit 36 is not provided in the region superimposed on thefirst domain 10 a and the region superimposed on the fourth domain 10 dand a second pixel electrode 35E having a configuration in which thefine slit 36 is provided in the two regions superimposed on the twotypes of domains (the first domain 10 a and the fourth domain 10 d) inwhich the fine slit 36 is not provided in the first pixel electrode 35Dwhile the fine slit 36 is not provided in the remaining two regions. Thefirst pixel electrode 35D and the second pixel electrode 35E arealternately arranged in the column direction. There are a row in whichthe first pixel electrode 35D is repeatedly arranged and a row in whichthe second pixel electrode 35E is repeatedly arranged.

The liquid crystal display device of the embodiment in FIG. 4 has a highunevenness improvement effect when viewed from a relatively distantposition, but the liquid crystal display device of the embodiment hasdiscomfort in the display depending on the image when viewed at a closedistance. For example, sometimes a two-line-period lateral line isvisible or granular feeling is felt when halftone solid display isobliquely viewed, and an edge of a box is seen jaggy in the display of abox-shaped image on a halftone background. On the other hand, in theliquid crystal display device of the first modification in FIG. 12, thegranular feeling at a close distance and the jaggy feeling at the edgeof the box are improved, and clear display is obtained.

FIG. 13 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules 41 in the liquid crystal layer 40 while theoblique azimuth is superposed on an example of the electrode and linestructure of the first substrate 30 according to a second modification.In the pixel electrode 35 of the second modification, the fine slit 36is provided in two regions located at the first and fourth positionsfrom one electrode end among the regions superimposed on the fourdomains, and the fine slit 36 is not provided in the two regions locatedat the second and third positions. In relation to the line, the fineslit 36 is provided in the domain located along the gate line G. Inrelation to the domain, the pixel electrode 35 of the secondmodification includes a first pixel electrode 35F having a configurationin which the fine slit 36 is provided in the region superimposed on thefirst domain 10 a and the region superimposed on the fourth domain 10 dwhile the fine slit 36 is not provided in the region superimposed on thesecond domain 10 b and the region superimposed on the third domain 10 cand a second pixel electrode 35G having a configuration in which thefine slit 36 is provided in the two regions superimposed on the twotypes of domains (the second domain 10 b and the third domain 10 c) inwhich the fine slit 36 is not provided in the first pixel electrode 35Fwhile the fine slit 36 is not provided in the remaining two regions. Thefirst pixel electrode 35F and the second pixel electrode 35G arealternately arranged in the column direction. There are a row in whichthe first pixel electrode 35F is repeatedly arranged and a row in whichthe second pixel electrode 35G is repeatedly arranged.

In the liquid crystal display device of the second modification in FIG.13, in the same manner as in the liquid crystal display device of thefirst modification in FIG. 12, as compared with the liquid crystaldisplay device of the embodiment, the granular feeling at a closedistance and the jaggy feeling at the edge of the box are improved, andthe clear display is obtained. Looking more closely the horizontal edgeof the box, sometimes the edge of the liquid crystal display device ofthe first modification may appear as a double line. However, in theliquid crystal display device of the second modification, this point isalso improved.

FIG. 14 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules 41 in the liquid crystal layer 40 while theoblique azimuth is superposed on an example of the electrode and linestructure of the first substrate 30 according to a third modification.The pixel electrode 35 of the third modification includes first pixelelectrodes 35H and 351 having an electrode structure in which the fineslit 36 is provided in two regions located at the first and thirdpositions from one electrode end among the regions superimposed on thefour domains while the fine slit 36 is not provided in the two regionslocated at the second and fourth positions and a third pixel electrode35J having an electrode structure in which the fine slit 36 is providedin the two regions located at the second and fourth positions from oneelectrode end while the fine slit 36 is not provided in two regionslocated at the first and third positions. In relation to the domain, thepixel electrode 35 of the third modification includes the first pixelelectrodes 35H and 351 having the configuration in which the fine slit36 is provided in the region superimposed on the first domain 10 a andthe region superimposed on the third domain 10 c while the fine slit 36is not provided in the region superimposed on the second domain 10 b andthe region superimposed on the fourth domain 10 d and the third pixelelectrode 35J having the configuration in which the fine slit 36 isprovided in the two regions superimposed on the two types of domains(the second domain 10 b and the fourth domain 10 d) in which the fineslit 36 is not provided in the first pixel electrodes 35H and 351 whilethe fine slit 36 is not provided in the remaining two regions.

In the liquid crystal display device of the third modification in FIG.14, as compared with the liquid crystal display device of theembodiment, density of the granule at a close distance is high, thegranular feeling and the jaggy feeling at the edge of the box areimproved, and the relatively clear display is obtained. The granularfeeling at the pixel edge is improved, and the relatively clearlydisplay is obtained.

FIG. 15 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules 41 in the liquid crystal layer 40 while theoblique azimuth is superposed on an example of the electrode and linestructure of the first substrate 30 according to a fourth modification.The fourth modification is different from the third modification havinga configuration of the two-line-period in that the domain array is oneline period. That is, the domains in the nth row pixel are arranged inthe order of the first domain 10 a, the second domain 10 b, the thirddomain 10 c, and the fourth domain 10 d, and the domains in the (n+1)throw pixel are arranged in the order of the first domain 10 a, the seconddomain 10 b, the third domain 10 c, and the fourth domain 10 d. Thepixel electrode 35 of the fourth modification includes a first pixelelectrode 35N having an electrode structure in which the fine slit 36 isprovided in two regions located at the first and third positions fromone electrode end among the regions superimposed on the four domainswhile the fine slit 36 is not provided in the two regions located at thesecond and fourth positions and a second pixel electrode 35P having anelectrode structure in which the fine slit 36 is provided in the tworegions located at the second and fourth positions from one electrodeend while the fine slit 36 is not provided in two regions located at thefirst and third positions. In relation to the domain, the pixelelectrode 35 of the fourth modification includes the first pixelelectrode 35N having the configuration in which the fine slit 36 isprovided in the region superimposed on the first domain 10 a and theregion superimposed on the third domain 10 c while the fine slit 36 isnot provided in the region superimposed on the second domain 10 b andthe region superimposed on the fourth domain 10 d and the second pixelelectrode 35P having the configuration in which the fine slit 36 isprovided in the two regions superimposed on the two types of domains(the second domain 10 b and the fourth domain 10 d) in which the fineslit 36 is not provided in the first pixel electrode 35N while the fineslit 36 is not provided in the remaining two regions.

In the liquid crystal display device of the fourth modification in FIG.15, as compared with the liquid crystal display device of theembodiment, the granular feeling at a close distance and the jaggyfeeling at the edge of the box are improved, and the relatively cleardisplay is obtained. As compared with the liquid crystal display devicesof the embodiment and the first to third modifications, thetwo-line-period horizontal stripe seen obliquely at a close distance isalso improved. On the other hand, when the liquid crystal display deviceof the fourth modification is viewed from a relatively distant distance,the unevenness improvement effect is slightly inferior to that of theembodiment and the first to third modifications.

FIG. 16 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules 41 in the liquid crystal layer 40 while theoblique azimuth is superposed on an example of the electrode and linestructure of the first substrate 30 according to a fifth modification.The fifth modification is different from the embodiment only in that thesolid electrode region does not exist at the domain boundary located inthe light transmission region to match the ends of the fine slits 36 ofthe pixel electrodes 35 of adjacent columns with each other. That is,when the pixel electrodes 35 of adjacent columns are translated andsuperposed, the region where the fine slit 36 does not exist does notexist at the boundary between the first region and the second regionfrom the pixel electrode end, and the region where the fine slit 36 doesnot exist does not exist at the boundary between the third region andthe fourth region from the pixel electrode end.

In the liquid crystal display device of the fifth modification in FIG.16, the luminance tends to be improved as compared with the liquidcrystal display devices of the embodiment and the first to fourthmodifications. On the other hand, the luminance is easily decreased whenthe misalignment is generated.

As illustrated in FIGS. 4 and 14 to 16, one of the two pixel electrodes35 of the adjacent column includes the fine slit 36 in the first regionfrom the end of the electrode but does not include the fine slit 36 inthe second region, and the other pixel electrode 35 does not include thefine slit 36 in the first region from the end of the electrode butincludes the fine slit 36 in the second region, and/or one of the twopixel electrodes 35 of the adjacent column includes the fine slit 36 inthe third region from the end of the electrode but does not include thefine slit 36 in the fourth region, and the other pixel electrode 35 doesnot include the fine slit 36 in the third region from the edge of theelectrode but includes the fine slit 36 in the fourth region. At thispoint, the arrangement of the fine slits 36 may have the followingfeatures.

-   -   The ends of the fine slits 36 of the pixel electrodes 35 of the        adjacent column are not matched with each other.    -   When the pixel electrodes 35 of the adjacent column are        translated and superposed, the region where fine slit 36 does        not exist exists at the boundary between the first region and        the second region from the pixel electrode end.    -   When the pixel electrodes 35 of the adjacent columns are        translated and superposed, the region where fine slit 36 does        not exist exists at the boundary between the third region and        the fourth region from the pixel electrode end.

As illustrated in FIGS. 4 and 14 to 16, one of the two pixel electrodes35 of the adjacent column includes the fine slit 36 in the first regionfrom the end of the electrode but does not include the fine slit 36 inthe second region, and the other pixel electrode 35 does not include thefine slit 36 in the first region from the end of the electrode butincludes the fine slit 36 in the second region, and/or one of the twopixel electrodes 35 of the adjacent column includes the fine slit 36 inthe third region from the end of the electrode but does not include thefine slit 36 in the fourth region, and the other pixel electrode 35 doesnot include the fine slit 36 in the third region from the edge of theelectrode but includes the fine slit 36 in the fourth region. At thispoint, the arrangement of the fine slits 36 may have the followingfeatures, and for example, the first substrate 30 in FIG. 16 satisfiesall the following features.

-   -   The ends of the fine slits 36 of the pixel electrodes 35 of the        adjacent column are matched with each other.    -   When the pixel electrodes 35 of the adjacent columns are        translated and superposed, the region where fine slit 36 does        not exist does not exist at the boundary between the first        region and the second region from the pixel electrode end.    -   When the pixel electrodes 35 of the adjacent columns are        translated and superposed, the region where fine slit 36 does        not exist does not exist at the boundary between the third        region and the fourth region from the pixel electrode end.

FIG. 17 is a schematic plan view illustrating the oblique azimuth of theliquid crystal molecules 41 in the liquid crystal layer 40 while theoblique azimuth is superposed on an example of the electrode and linestructure of the first substrate 30 according to a sixth modification.The sixth modification is different from the embodiment only in that theends of the fine slits 36 are not linearly arranged while the fine slitis thinned out.

In the liquid crystal display device of the sixth modification in FIG.17, as compared with the liquid crystal display devices of theembodiment and the first to fifth modifications, the unevennessimprovement effect tends to be slightly favorable when the liquidcrystal display device of the sixth modification is viewed from arelatively distant distance. On the other hand, there is a tendency thatthe luminance is slightly decreased.

In the present invention, the arrangement of the fine slits 36 may havethe following features. For example, the first substrate 30 in FIG. 17satisfies all the following features.

-   -   Some of the fine slits 36 are broken in the middle.    -   A pitch of the fine slits 36 changes within the pixel electrode.    -   The region where the pitch of the fine slits 36 is dense is        located at the pixel electrode end.    -   The region where the pitch of the fine slits 36 is dense has an        L shape, and is in two portions at the pixel electrode end.

Table 1 illustrates features of the embodiment and the first to sixthmodifications. As illustrated in Table 1, in the embodiment and thefirst to third and fifth modifications, the scanning unevennessimprovement effect is equal when viewed at a relatively long distance,but a difference in display quality exists when viewed at a relativelyclose distance. The first to third modifications are better than in theembodiment, particularly in second modification, the jaggy feeling ofedges is eliminated and the clear display is obtained. In the fourthmodification, although the scanning unevenness improvement effect isslightly inferior, the display quality at a close distance issatisfactory, so that the fourth modification is suitably used when thescanning unevenness can be improved by improving the manufacturingprocess or the like. Conversely, when problems such as the manufacturingprocess are large but the scanning unevenness cannot be expected to beimproved, the sixth modification is suitably selected.

TABLE 1 Domain array period in Slit and solid Corresponding columnelectrode arrangement drawing direction pattern Arrangement of fine slitEmbodiment FIG. 4 Two lines Half pixel has Sloid portion exists atcheckered pattern domain boundary located in transmission region FirstFIG. 12 Two lines Half-line stripe Sloid portion exists at modificationBoth ends are solid domain boundary located in electrode transmissionregion Second FIG. 13 Two lines Half-line stripe Sloid portion exists atmodification Central portion is domain boundary located in solidelectrode transmission region Third FIG. 14 Two lines Quarter pixel hasSloid portion exists at modification checkered pattern domain boundarylocated in transmission region Fourth FIG. 15 One line Quarter pixel hasSloid portion exists at modification checkered pattern domain boundarylocated in transmission region Fifth FIG. 16 Two lines Half pixel hasSloid portion does not exist modification checkered pattern at domainboundary located in transmission region Sixth FIG. 17 Two lines Halfpixel has Fine slit is thinned out modification checkered patternunevenness Abnormality viewed at comparatively close viewed at distancerelatively long Granular distance (such Lateral line feeling of asscanning feeling of gray gray scale Jaggy feeling unevenness) scaledisplay display of edge of box Embodiment (Comparison (Comparison(Comparison (Comparison reference) reference) reference) reference)First Equal Slightly inferior Good Good (however, modification edge hasa double line shape) Second Equal Slightly inferior Good Goodmodification Third Equal Equal Slightly good Slightly good modificationFourth Slightly Good Slightly good Slightly good modification inferiorFifth Equal Equal Equal Equal modification Sixth Good Equal Equal Equalmodification

Table 2 illustrates the feature of each element.

TABLE 2 Corresponding Element drawing Feature Domain array Two linesFIGS. 4, 12, Advantage: A complementary relationship between a pixelshape (upper and lower ends of pixel: period in 13, 14, 16, 17 A andcenter: B) and a combination of four domains 1 to 4 holds, and scanningunevenness column having viewing angle can be suppressed. An nth rowbecomes “1/A, 2/B, 3/B, 4/A”, an (n + 1)th direction row becomes “3/A,4/B, 1/B, 2I/A”, and both A and B are allocated to all the domains 1 to4. Disadvantage: Sometimes two-line-pitch lateral line unevenness isvisually recognized when obliquely viewed. Domains are arranged in acolumn direction in order of 3 × 4 × 3 × 4 × 1 × 2 × 1 × 2 × 3 × 4 × 3 ×4 × 1 × 2 × 1 × 2 . . . , and domains 3 and 4 are bright while domains 1and 2 are dark when viewed from the right, so that bright bright brightbright dark dark dark dark bright bright bright bright dark dark darkdark . . . are obtained to occasionally visually recognizetwo-line-pitch lateral line unevenness when viewed from the right.(bright and dark are reverse when viewed from the left) One line FIG. 15Advantage: When obliquely viewed, periodicity is minimum of one-linepitch, the two-line-pitch lateral line unevenness is not visuallyrecognized. Domain arrangement in the column direction is 1 × 2 × 3 × 4× 1 × 2 × 3 × 4 . . . , bright bright dark dark bright bright dark dark. . . to obtain a one-line period when viewed from the right.Disadvantage: There is deviation between the pixel shape and thecombination of the four domains 1 to 4, so that the scanning unevennesssuppression function in which the complementary relationship is useddoes not hold. The combination is “1/A, 2/B, 3/B, 4/A”, all the domain 1and 3 correspond to A, and all the domains 2 and 4 correspond to B.Slit/solid Half pixel has FIGS. 4, 16, Advantage: electrode checkeredpattern 17 Disadvantage: Granular feeling is conspicuous. In particular,granular feeling appears notably at arrangement horizontal-line boundaryedge when halftone solid display is performed or a white or black box ispattern displayed in a background of the halftone solid display.Half-line stripe FIG. 12 Advantage: The granular feeling is eliminated,and clear display is obtained. Both ends are Disadvantage: Lateral linefeeling is easily visually recognized. This is because the lateral linesolid electrode unevenness is superimposed on a bright and dark lateralline in halftone by slit and solid electrode arrangement. Domain arrayperiod in the column direction does not hold in one line, at least twoline are required. (For the viewpoint of eliminating deviation of theviewing angle) Half-line stripe FIG. 13 Advantage: The granular feelingis eliminated, and clear display is obtained. Central portionDisadvantage: Lateral line feeling is easily visually recognized. Thisis because the lateral line is solid unevenness is superimposed on abright and dark lateral line in halftone by slit and solid electrodeelectrode arrangement. Domain array period in the column direction doesnot hold in one line, at least two line are required. (For the viewpointof eliminating deviation of the viewing angle) Quarter pixel FIGS. 14,16 Advantage: Checkered-pattern dot has high density, and granularfeeling is improved. has checkered Disadvantage: Granular feeling is notcompletely eliminated. pattern Arrangement Solid portion FIGS. 4, 12,(Comparison reference) of fine slit exists at domain 13, 14, 15 boundarylocated in transmission region Solid portion FIG. 16 Advantage:Transmittance is slightly improved. does not Disadvantage: High accuracyis required for optical alignment process (division exposure) in existat domain manufacturing step, alignment between TFT substrate and CFsubstrate, and bonding. boundary located in transmission region Fineslit is FIG. 17 Advantage: Scanning unevenness improvement effect isimproved. thinned out Disadvantage: Luminance and transmittance tend tobe decreased.[Additional Remarks]

According to one aspect of the present invention, there is provided aliquid crystal panel including, in the following order: a firstsubstrate including multiple pixel electrodes arranged into a matrixform and a first alignment film; a liquid crystal layer containingliquid crystal molecules; and a second substrate including a commonelectrode and a second alignment film, wherein an alignment vector isdefined as being from a first substrate side long-axis end of each ofthe liquid crystal molecules, a start point, to a second substrate sidelong-axis end of the liquid crystal molecule, an end point, and thefirst alignment film and the second alignment film having been subjectedto an alignment treatment each include a first domain in which adirection of the alignment vector is a first direction, a second domainin which a direction of the alignment vector is a second direction, athird domain in which a direction of the alignment vector is a thirddirection, and a fourth domain in which a direction of the alignmentvector is a fourth direction, in a column direction in each display unitregion superimposed on one of the pixel electrodes, in at least 30pixels consecutive in a row direction, arrays of the domains areidentical, the domains in the display unit region located in an nth row,where n is any integer of 1 or more, are arranged in an order of thefirst domain, the second domain, the third domain, and the fourthdomain, and each of the pixel electrodes includes a first pixelelectrode having a configuration in which fine slits parallel to thealignment vector of the corresponding domain is provided in at least oneof a region superimposed on the first domain, a region superimposed onthe second domain, a region superimposed on the third domain, or aregion superimposed on the fourth domain while the fine slits are notprovided in the remaining regions.

In the above aspect, the fine slits may not be provided at both ends ofeach of the pixel electrodes in the column direction.

In the above aspect, the fine slits may not be provided up to an end ofeach of the pixel electrodes.

The pixel electrodes may include at least one of the followingcombinations (1) to (4):

(1) a combination of the pixel electrode in which the fine slits areprovided in the region superimposed on the first domain and the pixelelectrode in which the fine slits are not provided in the regionsuperimposed on the first domain;

(2) a combination of the pixel electrode in which the fine slits areprovided in the region superimposed on the second domain and the pixelelectrode in which the fine slits are not provided in the regionsuperimposed on the second domain;

(3) a combination of the pixel electrode in which the fine slits areprovided in the region superimposed on the third domain and the pixelelectrode in which the fine slits are not provided in the regionsuperimposed on the third domain; and

(4) a combination of the pixel electrode in which the fine slits areprovided in the region superimposed on the fourth domain and the pixelelectrode in which the fine slits are not provided in the regionsuperimposed on the fourth domain.

The first pixel electrode may have a configuration in which the fineslits are provided in two of the region superimposed on the firstdomain, the region superimposed on the second domain, the regionsuperimposed on the third domain, and the region superimposed on thefourth domain while the fine slit is not provided in the remaining tworegions.

The plurality of pixel electrodes may include the second pixelelectrode. The second pixel electrode is disposed adjacent to the firstpixel electrode, and have the configuration in which the fine slits areprovided in two regions superimposed on two types of domains in whichthe fine slits are not provided in the first pixel electrode while thefine slits are not provided in the remaining two regions.

In the above aspect, the first pixel electrode may have theconfiguration in which the fine slits are provided in the regionsuperimposed on the first domain and the region superimposed on thethird domain while the fine slits are not provided in the regionsuperimposed on the second domain and the region superimposed on thefourth domain, and the second pixel electrode may have the configurationin which the fine slits are provided in the region superimposed on thesecond domain and the region superimposed on the fourth domain while thefine slits are not provided in the region superimposed on the firstdomain and the region superimposed on the third domain.

In the above aspect, in a plan view of the display unit region, thealignment vector of the first domain and the alignment vector of thesecond domain may have a relationship in which the end points areopposed to each other and the alignment vectors are orthogonal to eachother, the alignment vector of the second domain and the alignmentvector of the third domain may have a relationship in which the startpoints are opposed to each other and the alignment vectors are parallelto each other, and the alignment vector of the third domain and thealignment vector of the fourth domain may have a relationship in whichthe end points are opposed to each other and the alignment vectors areorthogonal to each other.

The domains in the display unit region located in the (n+1)th row maysatisfy a relationship in which the first domain and the fourth domainare located between the second domain and the third domain.

The domains in the display unit region located in the (n+1)th row may bearranged in the order of the third domain, the fourth domain, the firstdomain, and the second domain.

In the above aspect, the first pixel electrode may have theconfiguration in which the fine slits are provided in two regionslocated at the first and third positions from one electrode end amongthe regions superimposed on the four domains while the fine slits arenot provided in the two regions located at the second and fourthpositions, and the liquid crystal panel may include the third pixelelectrode disposed adjacent to the first pixel electrode, the thirdpixel electrode having the configuration in which the fine slit isprovided in the two regions located at the second and fourth positionsfrom one electrode end while the fine slits are not provided in tworegions located at the first and third positions.

In the above aspect, the first pixel electrode may have theconfiguration in which the fine slits are provided in two regionslocated at the second and third positions from one electrode end amongthe regions superimposed on the four domains while the fine slits arenot provided in the two regions located at the first and fourthpositions, and the liquid crystal panel may include the fourth pixelelectrode disposed adjacent to the first pixel electrode, the fourthpixel electrode having the configuration in which the fine slits areprovided in the two regions located at the first and fourth positionsfrom one electrode end while the fine slits are not provided in tworegions located at the second and third positions.

The liquid crystal molecules may be aligned substantially vertically tothe first substrate and the second substrate when no voltage is appliedto the liquid crystal layer, and the liquid crystal molecules mayobliquely be aligned so as to be matched with each of the alignmentvectors of the first domain, the second domain, the third domain, andthe fourth domain when the voltage is applied to the liquid crystallayer.

An inter-substrate twist angle of the liquid crystal molecules may beless than or equal to 45° in the first domain, the second domain, thethird domain, and the fourth domain.

At least one of the first alignment film or the second alignment filmmay be a photo alignment film.

Preferably both the first alignment film and the second alignment filmare photo alignment films.

According to another aspect of the present invention, there is provideda method of manufacturing the liquid crystal panel of the above aspect,the method including forming the fine slits by photolithography, thephotolithography including irradiating a photosensitive resin formed ona conductive film with light through a mask in which a patterncorresponding to the fine slits is formed and multiple lenses.

According to still another aspect of the present invention, there isprovided a method of manufacturing the liquid crystal panel of the aboveaspect, wherein the alignment treatment performed on the photo alignmentfilm includes irradiating the photo alignment film with polarized lightemitted from a light source through a polarizer in an oblique direction,and a polarization axis of the polarizer is rotated in a range of −15°to +15° from a 45° azimuth such that an exposure direction on a surfaceof the photo alignment film is adjusted to the substantial 45° azimuthwith respect to a light irradiation direction.

What is claimed is:
 1. A liquid crystal panel comprising, in thefollowing order: a first substrate including multiple pixel electrodesarranged into a matrix form and a first alignment film; a liquid crystallayer containing liquid crystal molecules; and a second substrateincluding a common electrode and a second alignment film, wherein analignment vector is defined as being from a first substrate sidelong-axis end of each of the liquid crystal molecules, a start point, toa second substrate side long-axis end of the liquid crystal molecule, anend point, and the first alignment film and the second alignment filmhaving been subjected to an alignment treatment each include a firstdomain in which a direction of the alignment vector is a firstdirection, a second domain in which a direction of the alignment vectoris a second direction, a third domain in which a direction of thealignment vector is a third direction, and a fourth domain in which adirection of the alignment vector is a fourth direction, in a columndirection in each display unit region superimposed on one of the pixelelectrodes, in at least 30 pixels consecutive in a row direction, arraysof the domains are identical, the domains in the display unit regionlocated in an nth row, where n is any integer of 1 or more, are arrangedin an order of the first domain, the second domain, the third domain,and the fourth domain, and each of the pixel electrodes includes a firstpixel electrode having a configuration in which fine slits parallel tothe alignment vector of the corresponding domain is provided in at leastone of a region superimposed on the first domain, a region superimposedon the second domain, a region superimposed on the third domain, or aregion superimposed on the fourth domain while the fine slits are notprovided in the remaining regions.
 2. The liquid crystal panel accordingto claim 1, wherein the fine slits are not provided at both ends of eachof the pixel electrodes in the column direction.
 3. The liquid crystalpanel according to claim 1, wherein the fine slits do not extend to anend of each of the pixel electrodes.
 4. The liquid crystal panelaccording to claim 1, wherein the pixel electrodes include at least oneof the following combinations (1) to (4): (1) a combination of the pixelelectrode in which the fine slits are provided in the regionsuperimposed on the first domain and the pixel electrode in which thefine slits are not provided in the region superimposed on the firstdomain; (2) a combination of the pixel electrode in which the fine slitsare provided in the region superimposed on the second domain and thepixel electrode in which the fine slits are not provided in the regionsuperimposed on the second domain; (3) a combination of the pixelelectrode in which the fine slits are provided in the regionsuperimposed on the third domain and the pixel electrode in which thefine slits are not provided in the region superimposed on the thirddomain; and (4) a combination of the pixel electrode in which the fineslits are provided in the region superimposed on the fourth domain andthe pixel electrode in which the fine slits are not provided in theregion superimposed on the fourth domain.
 5. The liquid crystal panelaccording to claim 1, wherein the first pixel electrode has aconfiguration in which the fine slits are provided in two of the regionsuperimposed on the first domain, the region superimposed on the seconddomain, the region superimposed on the third domain, and the regionsuperimposed on the fourth domain while the first slits are not providedin the remaining two regions.
 6. The liquid crystal panel according toclaim 5, wherein each of the pixel electrodes includes a second pixelelectrode disposed adjacent to the first pixel electrode, the secondpixel electrode having a configuration in which the fine slits areprovided in two regions superimposed on two types of domains in whichthe fine slits are not provided in the first pixel electrode while thefine slits are not provided in the remaining two regions.
 7. The liquidcrystal panel according to claim 6, wherein the first pixel electrodehas a configuration in which the fine slits are provided in the regionsuperimposed on the first domain and the region superimposed on thethird domain while the fine slits are not provided in the regionsuperimposed on the second domain and the region superimposed on thefourth domain, and the second pixel electrode has a configuration inwhich the fine slits are provided in the region superimposed on thesecond domain and the region superimposed on the fourth domain while thefine slits are not provided in the region superimposed on the firstdomain and the region superimposed on the third domain.
 8. The liquidcrystal panel according to claim 1, wherein in a plan view of thedisplay unit region, the alignment vector of the first domain and thealignment vector of the first domain and the alignment vector of thesecond domain have a relationship in which the end points are opposed toeach other and the alignment vectors are orthogonal to each other, thealignment vector of the second domain and the alignment vector of thethird domain have a relationship in which the start points are opposedto each other and the alignment vectors are parallel to each other, andthe alignment vector of the third domain and the alignment vector of thefourth domain have a relationship in which the end points are opposed toeach other and the alignment vectors are orthogonal to each other. 9.The liquid crystal panel according to claim 1, wherein the domains inthe display unit region located in an (n+1)th row satisfy a relationshipin which the first domain and the fourth domain are located between thesecond domain and the third domain.
 10. The liquid crystal panelaccording to claim 9, wherein the domains in the display unit regionlocated in the (n+1)th row are arranged in an order of the third domain,the fourth domain, the first domain, and the second domain.
 11. Theliquid crystal panel according to claim 1, wherein the first pixelelectrode has a configuration in which the fine slits are provided intwo regions located at first and third positions from one electrode endamong the regions superimposed on the four domains while the fine slitsare not provided in the two regions located at second and fourthpositions, and each of the pixel electrodes includes a third pixelelectrode disposed adjacent to the first pixel electrode, the thirdpixel electrode having a configuration in which the fine slits areprovided in the two regions located at the second and fourth positionsfrom one electrode end while the fine slits are not provided in tworegions located at the first and third positions.
 12. The liquid crystalpanel according to claim 1, wherein the first pixel electrode has aconfiguration in which the fine slits are provided in two regionslocated at second and third positions from one electrode end among theregions superimposed on the four domains while the fine slits are notprovided in the two regions located at first and fourth positions, andeach of the pixel electrodes includes a fourth pixel electrode disposedadjacent to the first pixel electrode, the fourth pixel electrode havinga configuration in which the fine slits are provided in the two regionslocated at the first and fourth positions from one electrode end whilethe fine slits are not provided in two regions located at the second andthird positions.
 13. The liquid crystal panel according to claim 1,wherein the liquid crystal molecules are aligned substantiallyvertically to the first substrate and the second substrate when novoltage is applied to the liquid crystal layer, and the liquid crystalmolecules are obliquely aligned so as to be matched with the alignmentvectors of the first domain, the second domain, the third domain, andthe fourth domain when voltage is applied to the liquid crystal layer.14. The liquid crystal panel according to claim 1, wherein aninter-substrate twist angle of the liquid crystal molecules is less thanor equal to 45° in the first domain, the second domain, the thirddomain, and the fourth domain.
 15. The liquid crystal panel according toclaim 1, wherein at least one of the first alignment film or the secondalignment film is a photo alignment film.
 16. The liquid crystal panelaccording to claim 15, wherein both the first alignment film and thesecond alignment film are photo alignment films.
 17. A method ofmanufacturing the liquid crystal panel according to claim 15, whereinthe alignment treatment performed on the photo alignment film includesirradiating the photo alignment film with polarized light emitted from alight source through a polarizer in an oblique direction, and apolarization axis of the polarizer is rotated in a range of −15° to +15°from a 45° azimuth such that an exposure direction on a surface of thephoto alignment film is adjusted to the substantial 45° azimuth withrespect to a light irradiation direction.
 18. A method of manufacturingthe liquid crystal panel according to claim 1, the method comprisingforming the fine slits by photolithography, the photolithographyincluding irradiating a photosensitive resin formed on a conductive filmwith light through a mask in which a pattern corresponding to the fineslits is formed and multiple lenses.